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CONTENTS

1. Introduction:
BMW Innovation Day 2006.
EfficientDynamics.

2. BMW Drivetrain Development:
Consistent Progress for EfficientDynamics.

2.1 Maximum Efficiency for Maximum Performance:
BMW Presents the Future of the Turbocharged Power Unit.

2.3 Dynamics and Efficiency in Perfect Harmony:
The World’s First Direct Gasoline Injection Power Unit with a Significant Edge in Fuel Economy.

2.6 Responsive and Precise:
Automatic Transmission Perfect also for the Sporting and Active Driver.

2.7 More Efficient Use of the Flow of Energy:
Intelligent Alternator Control and Recycling of Brake Energy.

3. BMW Materials Technology: Integrated Know-How from Research to Production.

3.1 Supreme Function the Light Way:
Intelligent Development of Materials in Body and Engine Construction.

1. BMW Innovation Day 2006. EfficientDynamics.

The dedicated motorist choosing a BMW should always be certain that he or she is purchasing a car able to offer maximum driving pleasure on the highest possible level of all-round economy. And under the term “EfficientDynamics”, BMW sums up all development activities serving to achieve this supreme standard.

At the Innovation Day 2006, BMW is presenting the latest developments in drivetrain technology, energy management, and materials technology which help to convincingly fulfil current and future-oriented customer wishes for even more efficient energy concepts and to master the challenges of tomorrow. Customer demand for vehicles offering higher output and performance together with increasingly diverse comfort and safety functions, and all this on less fuel, requires the utmost of the specialist in automotive development.

Innovation overcoming conflicts of interest.
Striving for EfficientDynamics, BMW is pursuing a strategy fit for the future and setting the trend in every respect. This strategy leads to vehicles reflecting the core value of the BMW brand – Sheer Driving Pleasure – in the same way as they meet the demands of the modern, future-oriented customer. The EfficientDynamics concept therefore consistently relates all factors of performance, fuel consumption, and weight to one another, providing target-oriented innovations on the drivetrain, in lightweight technology and aerodynamics, and providing the further option to overcome conflicts of interest.

Some of the latest achievements of this kind are presented at the BMW Innovation Day 2006. The combustion engines featured in BMW’s current models, for example, are not only exceptionally powerful, but also, through their high degree of all-round efficiency, make a significant contribution in reaching the objectives described. Intelligent use of materials and modern production technology, in turn, serve to limit the weight of vehicles despite their growing range of features and equipment.

Moving consistently from research to production.
The philosophy of EfficientDynamics covers all areas of automobile development within the BMW Group. And since this includes the development of fundamentally new solutions, researchers in materials technology search consistently for new materials helping to optimise the weight of the car and enhance driving pleasure accordingly.

BMW Group specialists working in this area have a level of competence and know-how truly outstanding not only within the automotive industry. Indeed, in the demands they make of new materials, BMW’s development specialists set significant standards in the area of materials research. And at the same time they are in a position to upgrade the latest findings in scientific research quickly and efficiently to the standard of perfection required for practical use. As a result, the customer receives a vehicle which, in the sum total of its qualities, always represents the latest state of the art – which means also making specific parts and components out of materials which did not even exist before in this form and thus give a BMW truly unique qualities.

The front side panel on the BMW 3 Series Coupé, for example, is made of a synthetic material never used before and therefore exclusive to BMW. Also in terms of design freedom and temperature resistance, this extremely light component offers qualities no synthetic material was ever able to provide before.

The leadership in technology of the BMW Group thus provides customer benefits only BMW is able to offer: the front side panel in the BMW 3 Series Coupé is not only lighter than a conventional side panel made of steel, but also sustains less damage in a minor impact.

The BMW Group is likewise fully consistent in engine development, proceeding from the theoretical concept to the actual driving experience. But the approach taken in this case need not necessarily be the fastest one, since it is also part of BMW’s philosophy to weigh the assets of the brand against the benefits actually offered to the customer in introducing a new technical solution.

With every new BMW offering an enhanced level of driving dynamics, the driver must feel this improvement directly. And the same applies to the improvement of fuel economy – which is precisely why BMW deliberately decided against introducing the first generation of direct gasoline injection, since the fuel savings possible in this case were limited to a narrow engine speed range and therefore failed to fulfil the great demands made of a BMW in its all-round qualities.

The BMW Group’s engine development specialists were however most certainly able to distinguish between the fundamental potential of direct gasoline injection and the initial – but rather limited – implementation of the concept. They therefore decided to develop VALVETRONIC throttle-free load management, a technology able to immediately provide much greater benefits in fuel economy, without losing sight of fundamental developments in the area of direct gasoline injection. And now the result is here: Introducing High Precision Fuel Injection, BMW is presenting the first power unit featuring second-generation direct gasoline injection and thus providing a significant reduction of fuel economy throughout a broad range of engine speed and load and, accordingly, under standard, everyday driving conditions.

Superior competence with a far-reaching effect.
With High Precision Fuel Injection being introduced step-by-step in an increasingly large number of model series and markets, the benefits of this technology will soon become available to a large number of customers. This broad-scale effect is important to BMW in order to measure the value of a genuine innovation in the market.

Taking the example of intelligent energy management, we see clearly that various steps in the development process can be consistently based on one another. The actual generation and use of electric energy is already masterminded with a high degree of efficiency in BMW models already successful in the market today. Future systems will serve to avoid the loss of energy to the greatest possible extent. Where that is not possible, losses will be intelligently transformed into useful forms of energy, such as the use of brake energy via Brake Energy Regeneration.

Hybrid concepts: proceeding step-by-step to series maturity.
Using Brake Energy Regeneration interacting with Intelligent Alternator Control (IAC) developed by BMW, the generation of electrical energy can now be shifted specifically and in a controlled process to the car’s overrun and braking phases, converting brake energy instead of fuel into electric power. When driving under power (in traction or power phases), the energy potential provided by the fuel can be used to a greater extent to generate kinetic energy and motion, giving the car greater, enhanced dynamics. This effect clearly noticeable at the wheel is referred to as passive boosting.

With the management of electrical energy flow by means of IAC giving the vehicle a higher standard of driving dynamics “only” in an indirect process, development engineers refer to this technology as “mild-hybridisation”.

The interaction of primary and electric energy becomes even more effective in the next stage, the classic hybrid concept using electric energy directly and as a supplementary driving force to power the vehicle while running on the combustion engine at the same time. This generates an active boost effect, the electric motor supporting the combustion engine in generating dynamic power and motion.

When the car is able to run in various driving situations not just on the combustion engine, but also under electric power alone, we speak of “full-hybridisation”.

BMW’s concept of Intelligent Alternator Control (IAC) is on the verge to achieving production standard and was already presented at the 2005 Frankfurt Motor Show in the guise of the BMW Concept X3 EfficientDynamics. This concept car featuring Active Transmission and High-Performance Capacitors (supercaps) stands out clearly from other hybrid concepts. Its drive system ensures not only greater economy, but also a higher standard of dynamic performance by combining the output of the combustion engine and the electric motor with all their qualities. The result is maximum torque of 600 Newton-metres or 442 lb-ft for accelerating particularly fast and dynamically from engine speeds below 1,500 rpm, using the power delivered by both drive motors. In practice, this means acceleration to 100 km/h in 6.7 seconds and a top speed of 235 km/h or 146 mph. And as the name indicates, this concept car is based on the BMW X3.

Hydrogen drive: driving from today into the future.
The use of hydrogen for driving a vehicle points even further into the future, potentially offering even greater benefits. Hence, BMW’s CleanEnergy concept offers all the features and qualities required for a sustained strategy of mobility. Apart from the BMW H2R Research Vehicle, various BMW demonstration vehicles running on hydrogen are already in use today. Completing a wide range of tests under near-practical conditions, these vehicles serve to study and confirm the qualities of hydrogen drive under everyday driving conditions.

In the CleanEnergy project BMW is concentrating on the use of hydrogen in the combustion engine. This technology is lighter, more powerful and less expensive than the – conceivable – use of fuel cells. A further advantage is that production of the hydrogen combustion engine can be integrated into existing production processes.

The superior performance and great appeal of hydrogen drive developed to this standard is obvious. With its twelve-cylinder power unit developing 210 kW/285 hp maximum output, the BMW H2R Research Car has set up several records for hydrogen drive vehicles. A BMW powered by a hydrogen combustion engine is already in the process of series development and will be presented to the public in the course of the next two years.

2. BMW Drivetrain Development: Consistent Progress for EfficientDynamics.

The overall framework for developing innovative technologies of the type described is set by the lawmaker – while the actual process of implementation is determined by the customer. But still, engine development at BMW is influenced only indirectly by external factors, since the Company’s fundamental urge in striving for new innovations time and again follows from the self-perception of the BMW brand, the competence in technology of the BMW Group, and the demands thus made of BMW products.

“Sheer Driving Pleasure” is the motivation underlying not only the customer’s expectations, but also the demands made of BMW’s engineers. But driving pleasure these days is a function not only of superior dynamics, but also of enhanced efficiency. A conscious experience of Sheer Driving Pleasure therefore also means the knowledge of not having to pay for extra dynamics by way of excessive fuel consumption.

Precisely this is why the BMW Group has established the general development target of EfficientDynamics with very clear standards and criteria. And with each new generation of engines providing the qualities for even better performance, each new power unit also serves to enhance all-round economy to an even higher standard.

BMW already sets the standard in EfficientDynamics today through the gasoline and diesel engines the Company offers to the market. These power units are the result of a consistent process of development with an equal focus on enhanced performance and the optimisation of fuel consumption. The drive units featured in the BMW Group’s current models also offer the potential to achieve further progress in future in both areas, with innovations in technology resting on and supplementing one another.

More power, comfort, and safety – but on less fuel.
A comparison of engine concepts from former decades with the power units offered to the customer today clearly confirms the progress achieved: Looking at a BMW 323i in the 1983 model year versus the current BMW 325i – both of these models featuring a straight-six power unit – we immediately see the substantial difference: Engine output is up by 57, maximum torque by 24 per cent. Acceleration, in turn, has improved by 24 per cent. And while vehicle weight is up by 38 per cent, the drag coefficient is 16 per cent lower. Fuel consumption is now 20 per cent below the figure in 1983, and emission management has improved by no less than 95 per cent.

These figures alone confirm the great extent to which progress is committed to the overriding objective of EfficientDynamics. A modern car offers more space, more comfort, and more safety. Hence, it is larger and heavier than former models in the same segment. But the larger frontal area has been more than set off by improvements in aerodynamics, while the use of modern materials has been able to keep the increase in weight within limits, without however setting off this increase completely.

With fuel consumption not increasing under these circumstances, but – quite on the contrary – decreasing most significantly, we see and learn to appreciate the very substantial improvement in efficiency offered by a modern power unit. Benefiting from lower friction, optimised combustion and a more efficient charge cycle, a modern power unit offers significantly greater dynamics and a very noticeable decrease in fuel consumption. Further efficiency is added by new transmissions with a larger number of gears and, as a result, an optimised spread of gear ratios.

This reduction of fuel consumption is accompanied by a significant decrease in emissions. Indeed, elaborate and sophisticated management of exhaust emissions ensures full compliance with legal standards and limitations now allowing only a fraction of the emission levels permitted in former times.

Innovations with a lasting effect.
BMW has set numerous milestones in the course of this development history clearly marked out by the above comparison: Proceeding from four-valve technology via variable VANOS valve management and double-VANOS all the way to fully variable VALVETRONIC valve management, BMW has presented outstanding innovations time and again. And in each case these innovations have served to reduce fuel consumption and emissions, while consistently increasing engine output and performance.

These innovative systems have many features in common: They are used in engines of various size, configuration and design. They supplement one another and provide the effect desired also in everyday traffic. And therefore they are never just short-term, fleeting solutions. On the contrary – four-valve technology is now state-of-the-art in a whole range of drive units, VANOS and VALVETRONIC are featured in engines with a various number of cylinders and will play a major role also in engines of the future.

Following a clear BMW principle, all new developments must fulfil their function consistently and with sustainable effect. On the diesel engine, direct fuel injection is already meeting this demand in the third generation. And now BMW offers a technology of this kind leading the way in the gasoline engine towards a genuine, significant reduction of fuel consumption: High Precision Fuel Injection now being presented by BMW as the second generation of direct gasoline injection ensures a supreme standard of all-round flexibility. This technology is featured in the new, particularly powerful and dynamic Twin-Turbo straight-six, and may also be operated as lean-burn direct fuel injection.

Contrary to the first generation of direct gasoline injection, which failed to offer the aspired improvement of fuel economy in everyday traffic and was therefore not taken up by BMW, High Precision Fuel Injection makes a significant contribution to EfficientDynamics in every respect.

Energy flow management on two levels.
In addition to this breakthrough technology, BMW is also pursuing a strategy of intelligent energy flow management throughout the Company’s entire range of engines, a strategy benefiting all engines regardless of size, configuration, and technical specifications.

In this case the loss of energy is avoided from the start on two levels: Automatic engine start/stop serves to prevent the loss of primary energy and is activated whenever the engine is idling. The automatic start/stop technology used by BMW switches off the drive unit for example when stopping at traffic light. Then, to start the engine again, all the driver has to do is press the clutch pedal. Provisional calculations based on the EU test cycle show that this function alone is able to reduce the average fuel consumption of a BMW 3 Series by up to 0.5 litres/100 kilometres.

The second level of energy flow management focuses on the generation, storage and use of electric energy on board the vehicle. Electric energy is required to operate numerous comfort, safety, and dynamic functions. Intelligent Alternator Control developed by BMW serves to shift the conversion of primary energy into electric power entirely into the overrun and braking phases, thus providing more engine power for the generation of kinetic energy during the real power phases with the engine actually “pulling” the car. A further point is that the regeneration of brake energy allows the use of additional reserves previously remaining untapped and unused.

Applying this concept referred to as Brake Energy Regeneration, BMW converts energy previously escaping unused as thermal energy from the brake discs into electric power, thus generating additional energy for the on-board network every time the driver applies the brakes.

Depending on driving conditions and the current mode of engine operation, such a managed or masterminded flow of energy serves to provide enhanced dynamics and efficiency in converting fuel into motion, heat and electrical energy.

The technology required for this purpose is on the verge to reaching production standard at BMW. And since these systems may be used in engines of various configuration and size, a large number of customers is able to benefit from their advantages, once again enjoying even better dynamics on even less fuel.

This wide range of potential benefits and practical use is of great significance to BMW also for another reason, since such a diversity of technologies serves to minimise fleet consumption and exhaust emissions in order to reach the strictest requirements and standards without impairing Sheer Driving Pleasure at the wheel.

2.1 Maximum Efficiency for Maximum Performance: BMW Presents the Future of the Turbocharged Power Unit.

A new top-of-the-range power unit with Twin-Turbo Technology and direct gasoline injection will form the pinnacle of BMW’s wide range of straight-six power units in future. Developing maximum output of 225 kW/306 hp and peak torque of 400 Newton-metres or 295 lb-ft, this new engine offers the highest standard of spontaneous and superior power and performance any customer can expect.

The first straight-six with twin turbochargers, High Precision Fuel Injection and an all-aluminium crankcase offers a level of responsiveness never seen before on a turbocharged engine as well as supreme power and torque extending all the way to high engine speeds. A further benefit of this new turbocharged power unit is the running smoothness typical of a BMW straight-six.

Particular efficiency in achieving this supreme power is ensured by BMW’s High Precision Fuel Injection, the second generation of direct gasoline injecttion making a significant contribution to the enhanced economy of the Twin-Turbo power unit. Indeed, introducing this combination of technologies, the BMW Group, 100 years after the invention of the turbocharged engine, has written a new and particularly attractive chapter in the history of turbocharging.

Resting on a proven basis: the straight-six power unit.
Introducing turbocharger technology, BMW is providing both a fascinating and efficient answer to the driver’s wish for additional power and performance. Particularly with the concept chosen by BMW, turbocharging is simply ideal in preserving the proven qualities of the drivetrain and creating other new, appealing features.

This technology is being introduced on the basis of BMW’s current generation of straight-six power units displacing 3.0 litres and developing maximum output of 195 kW/265 hp, that is a potential already quite outstanding for a normal-aspiration engine. Now, to generate a further significant increase in power and, in particular, more torque, BMW is introducing Twin-Turbo technology, boosting output over the proven 3.0-litre normal-aspiration engine by about 15, and torque by approximately 30 per cent.

Absolute ratings of 225 kW/306 hp maximum output and 400 Newton-metres or 295 lb-ft peak torque tell the whole story, clearly proving the supreme muscle offered by the new power unit from low engine speeds. And what this means in practice BMW’s engine development specialists have already calculated, taking the BMW 3 Series Saloon as an example: The Twin-Turbo version accelerates from 0–100 km/h more than half a second faster and completes the flexibility test (80–120 km/h or 50–75 mph in second-highest gear) in 6.3 seconds, leaving the most powerful normal-aspiration version, the BMW 330i, far behind at 8.2 seconds.

Retaining the normal-aspiration engine concept, such an increase in dynamic performance would only have been possible by significantly enlarging the size of the engine, which would also have meant a corresponding increase in weight and corresponding effects on the car’s balance.

Using turbocharger technology in conjunction with High Precision Fuel Injection, on the other hand, BMW has found a particularly efficient method to meet significantly greater demands in terms of both power and torque. Just for comparison, the new Twin-Turbo straight-six weighs approximately 70 kilos or 154 lb less than a comparably powerful natural-aspiration eight-cylinder displacing 4.0 litres. And compared with an equally powerful turbocharged engine featuring intake manifold fuel injection, the new power unit with High Precision Fuel Injection offers approximately 10 per cent better fuel economy.

Apart from lower weight and a standard of fuel economy by all means favourable in its performance class, the new Twin-Turbo offers yet another quality feature typical of a BMW straight-six: This is outstanding running smoothness and, as a result, precisely the virtue which has made BMW’s six-cylinder inline power units the world standard for refined drive technology. Right from the start, the arrangement of cylinders gives the engine perfect balance and smoothness in terms of free mass forces, avoiding vibrations also at high engine speeds.

A further aspect is that the turbocharged version of the six-cylinder comes with the particularly light camshafts already boasted on the normal-aspiration power unit, double-VANOS variable camshaft adjustment, and an electrically driven coolant pump operating only when and to the extent to which it is actually required.

The turbo “gap” – a thing of the past.
Introducing this revolutionary engine technology, BMW’s engineers have succeeded in once and for all eliminating the previously inherent disadvantages of a turbocharged power unit. Hence, BMW’s new Twin-Turbo six-cylinder is not encumbered by the features so typical of turbocharged engines in general to this day: There is no time-lag before power and torque cut in, and the engine does not have the high fuel consumption so typical of a conventional turbocharged power unit. Particularly the Twin-Turbo arrangement ensures a much more responsive development and build-up of power, two smaller turbochargers each supplying compressed air to three cylinders instead of one large turbocharger serving all six cylinders.

The big advantage of such small turbochargers is their low inertia momentum, even the slightest movement of the gas pedal by the driver’s foot serving to immediately build up superior pressure and power. Clearly, this puts an end once and for all to the turbo “gap” previously so typical of a turbocharged power unit – the time lag required until the turbocharger starts to really boost power.

On the road, therefore, the new Twin-Turbo power unit offers the same muscle as a much larger normal-aspiration engine, the 3.0-litre developing supreme torque of 400 Newton-metres or 295 lb-ft without any noticeable delay consistently throughout the engine speed range from 1,300 to 5,000 rpm.

And even that is not everything, with the engine continuing to rev up smoothly to a speed range of approximately 7,000 rpm. This obviously gives the driver a particularly superior thrill of driving dynamics, allowing him to accelerate quickly and smoothly whenever required, for example when overtaking another vehicle.

Substantial progress in two respects: more power, more efficiency.
To combine a truly thrilling driving experience with a standard of fuel economy appropriate in this day and age, BMW has become the world’s first car maker to develop a straight-six gasoline engine complete with twin turbocharger technology, direct gasoline injection, and an all-aluminium crankcase.

Through their concept alone, the turbochargers already make an important contribution to enhanced fuel economy: With the turbines made of high heat-resistant special steel able to handle temperatures of up to 1,050 °C or 1,900 °F, there is no need for the cooling effect of enhanced fuel supply. The result, particularly under full load, is a significant reduction of fuel consumption on the road.

High Precision Fuel Injection nevertheless performs the key function in this concept for maximum fuel efficiency: The new generation of BMW’s direct gasoline injection power units meets all expectations also in practice in terms of fuel economy, without requiring any compromise in the engine’s dynamic qualities. Indeed, High Precision Fuel Injection allows even more exact dosage of the fuel/air mixture as well as a higher compression ratio – simply ideal for an increase in efficiency and a significant reduction of fuel consumption in practice.

All this is made possible by the central position of the piezo-injector between the valves. In this position the innovative injector opening up to the outside is able to distribute fuel in a conical, particularly consistent spread throughout the combustion chamber.

Developing the new straight-six power unit with twin turbocharger technology and direct fuel injection, BMW is opening up a new chapter for an engine principle actually quite old: Only recently the turbocharged engine celebrated its 100th birthday, turbocharger technology registered for a patent by Swiss engineer Alfred Büchi in November 1905 playing an important role for decades particularly in the enhancement of marine and aircraft engines. It was only much later that cars with turbocharged power units started to come off the production line, the first series model in Europe to boast this technology being the BMW 2002 turbo in 1973.

BMW – the first turbocharged World Champion in the history of Formula 1.
Throughout the history of the turbocharger now going back 100 years, BMW has set milestones in development time and again. As early as in the late ’60s of the former century, BMW became the first manufacturer to use turbocharged engines in touring car racing. And in 1983 a BMW Brabham with Brazilian racing driver Nelson Piquet at the wheel became the first turbocharged racing car to win the Formula 1 World Championship. Even back then, BMW’s engine specialists were able to get far more than 1,000 hp out of an engine displacing only 1.5 litres.

Ultimately, however, the apparently unlimited options in boosting engine power through turbocharger technology led to the decision in the highest realms of motorsport to stop the ongoing escalation of engine power for reasons of safety.

In series production, on the other hand, all turbo concepts used so far have always been seen as uneconomical in terms of their fuel consumption. Indeed, this conflict of interests appeared to be inevitable for a long time, with no solution in sight. So only the most recent developments in engine construction have opened up the door to a new approach BMW is now taking consistently: Twin-Turbo technology in conjunction with High Precision Fuel Injection as the concept for a particularly thrilling manifestation of EfficientDynamics.

The new high-performance power unit ranking right at the top of BMW’s straight-six engine line-up impressively proves the potential of this concept and its most important components. Ensuring superior response and supreme pulling force, the new power unit about to enter series production opens up brand-new dimensions in driving dynamics.

Introducing High Precision Fuel Injection, BMW’s engine development specialists have also prepared for another option in innovative technology. For over and above the benefits of supreme dynamics provided by the engine, the new technology sets the foundation for a lean-burn direct injection concept ensuring significant optimisation of fuel economy also in other performance classes. In this way BMW is once again using its leading competence in engine construction in order to develop modern, up-to-date drive technology and at the same time enhance Sheer Driving Pleasure to a new standard never seen before.

2.3 Dynamics and Efficiency in Perfect Harmony: The World’s First Direct Gasoline Injection Power Unit with a Significant Edge in Fuel Economy.

Enhanced driving dynamics, optimum weight reduction, and minimisation of fuel consumption – these are the objectives pursued by BMW’s engine development specialists under the philosophy of EfficientDynamics. And this is why each new generation of engines offers progress in technology the driver will feel directly on the road and the engineer is able to measure just as directly in practice.

Direct gasoline injection has now reached the level of perfection required for use in a BMW straight-six. So introducing High Precision Fuel Injection, BMW is presenting the world’s first second-generation direct injection power unit able to offer significant fuel savings also in everyday use, without making any kind of compromise in terms of power and performance.

Operating with lean-burn direct injection in the straight-six normal-aspiration power unit, this technology serves to cut fuel consumption by another 10 per cent in the EU test cycle compared with the already very efficient power unit featuring fully variable valve drive the new engine is based on. Hence, High Precision Fuel Injection differs significantly from first-generation direct gasoline injection which, for good reason, BMW never used in order to reduce fuel consumption. A further advantage of the new technology is that it retains all of the qualities so typical of the world’s most innovative and technically demanding straight-six – dynamic power and performance, fast-revving engine response, and exemplary running smoothness – without making the slightest compromise.

Developing maximum output of 200 kW/272 hp and peak torque of 315 Newton-metres or 232 lb-ft, the new 3.0-litre with High Precision Fuel Injection outperforms even the most powerful straight-six with the same displacement featured so far in a BMW production car.

Thrilling dynamics, convincing economy.
The newly developed drive unit is conceived as a normal-aspiration engine running in the lean-burn mode. This means extremely economical dosage of gasoline in the fuel air/mixture, with the piezo-injectors positioned directly next to the spark plugs ensuring particularly precise fuel injection without the slightest loss of fuel.

At the same time BMW’s engine development specialists have succeeded in combining this supreme efficiency with equally thrilling performance. The engine, which again is on the verge of reaching production maturity, will thrill the motorist first and foremost through its dynamic performance so typical of BMW – just as the motorist will subsequently be convinced at the filling station by unusually good fuel economy. The bottom line, therefore, is that the first six-cylinder normal-aspiration power unit with direct gasoline injection meets all the requirements of EfficientDynamics in both areas.

It is particularly these benefits when driving and filling up the tank which make the new power unit so superior to the first generation of direct-injection gasoline engines. Because so far the high hopes placed in this technology for a considerable reduction of fuel consumption in everyday motoring have simply not been fulfilled.

Precisely this was why BMW decided to skip the first generation of direct gasoline injection with its inherent disadvantage of being able to save fuel in practice only within a narrow load range at low engine speeds. Recognising this inherent drawback right from the start, BMW’s engine development specialists took on the challenge to develop an alternative solution for minimum fuel consumption. This led to the introduction of BMW’s throttle-free VALVETRONIC engine load management in the year 2001, a new technology which immediately served to significantly reduce fuel consumption on a reliable, consistent and measurable basis. Today VALVETRONIC is featured throughout BMW’s entire model range and has proven its value in more than a million cars.

Innovative piezo-injectors positioned perfectly within the combustion chambers.
VALVETRONIC will continue to play a major role worldwide in six-cylinder power units. But parallel to the introduction of VALVETRONIC, BMW was also working all-out on enhancing direct gasoline injection to a standard appropriate for the great demands made of a BMW car and the BMW brand.

This technology was however only able to offer its real potential through the development of High Precision Fuel Injection: Innovative piezo-injectors supplying fuel into the cylinders at a pressure of 200 bar allow particularly fine dosage of the fuel/air mixture. The newly developed injectors arranged between the valves in the cylinder head are able to cope with the high temperature and pressure loads prevailing in that area, the injector needles responding extremely quickly and consistently to the injection pulses conveyed electronically by the engine control unit. Accordingly, the new piezo-injectors offer perfect qualities and features for an exact supply of fuel and, as a result, for a well-controlled, clean and efficient combustion process.

BMW’s engineers have furthermore succeeded in positioning the injectors directly next to the spark plug, despite the very confined space available. In this position the piezo-nozzles opening to the outside ensure a stable and conical injection jet entering the combustion chamber.

Contrary to fuel injection running along the walls in the past, this new jet-based process allows much faster and, in particular, much more efficient preparation and supply of the fuel/air mixture. The mixture itself is formed in the direct vicinity of the spark plug, thus avoiding the loss of fuel otherwise encountered with the conventional injection of fuel along the walls of the combustion chamber.

The result is a stratified cylinder charge with all its benefits also in the lean- burn mode, various intersecting layers of the fuel/air mixture forming within the combustion chamber.

In this case the share of gasoline in the mixture decreases with a growing distance from the spark plug, the fuel/air mixture being particularly rich and therefore able to ignite only in the direct vicinity of the spark plug. Then, as soon as the fuel/air mixture ignites, the lean layers further away from the spark plug will also burn in a smooth, clean and consistent process.

Economic and powerful all the way to high engine speeds.
Through their particular design and configuration, as well as their optimum position, the injectors ensure high precision in the fuel/air mixture formation process throughout a broad range of operation. This allows the lean-burn mode to be maintained well into higher engine speed and load ranges, which is indeed a significant reason for the greater fuel economy of High Precision Fuel Injection versus first-generation direct gasoline injection.

Another reason for not using first-generation direct gasoline injection in BMW engines was the fact that this technology actually reduced and dampened the power and performance of the engine: With the measures taken to swirl fuel and air via flaps in the intake manifold consuming some of the engine power, such engines introduced with the first generation of direct gasoline injection suffered a significant loss in efficiency and maximum output. But now this problem has been solved, BMW’s new straight-six with High Precision Fuel Injection being able to breathe much more easily and smoothly than conventional engines with direct injection.

High Precision Fuel Injection: writing a new chapter in an outstanding story of success.
The introduction of direct gasoline injection in the straight-six power unit is the result of an integrative strategy of development consistently pursued by BMW. The objective is to retain the existing qualities of a superior engine concept and to further enhance the engine’s fortes through innovations in technology. Hence, the power unit equipped with High Precision Fuel Injection writes a new chapter in the consistent story of development of BMW’s six-cylinder inline power units.

The foundation for this latest development is set by the most demanding engine of its kind in the world in terms of the flow of power, the power-to-weight ratio, and running refinement: BMW’s six-cylinder featuring a composite magnesium/aluminium crankcase. The reduction in weight provided by the use of magnesium as a particularly light material has a very positive effect on both the economy and agility of all cars driven by this power unit. Likewise, the specially developed lightweight camshafts made in a hydroforming process also serve to optimise the weight of the engine. The electrical coolant pump, in turn, is operated as a function of temperature and only runs when really needed, again helping to enhance engine efficiency. Consuming just 200 Watt, the coolant pump requires only a tenth of the drive energy otherwise used to run a conventional pump.

Introducing direct gasoline injection, BMW is taking yet another major step in enhancing the efficiency of its straight-six power unit. Retaining all the features and characteristics so typical of this engine, High Precision Fuel Injection is becoming a new highlight on the six-cylinder. One of the special achievements in engineering is that the new piezo-injectors have been fully integrated without requiring any compromises in the design and configuration of the cylinder head and pistons. The engine thus maintains its original character based on free-revving performance and outstanding running smoothness, despite the optimisation of all-round efficiency.

With maximum output of 200 kW/272 hp and peak torque of 315 Newton-metres or 232 lb-ft, this is also the most powerful version so far of BMW’s 3.0-litre six-cylinder normal-aspiration engine. And on the road, this means two advantages in one: a further increase in engine dynamics and a new dimension in all-round economy.

Clean and intelligent: NOx storage catalysts.
BMW’s new straight-six power unit with High Precision Fuel Injection is being launched initially in the European markets. Then, with sulphur-free fuel becoming increasingly available also elsewhere as the prerequisite for the NOx storage catalyst technology featured in the engine, the new power unit will make its entry step-by-step into other markets.

Yet a further advantage is that European customers will also be able to use their car in countries where sulphur-free fuel is not yet available everywhere. While in such cases the engine will not be able to offer its particular fuel economy in full, since in that case the storage catalyst will require regeneration more often than when running on fuel free of sulphur, there are no objections to running the engine also on fuel containing sulphur, when a European customer travels abroad.

2.6 Responsive and Precise: Automatic Transmission Perfect also for the Sporting and Active Driver.

All you do is press the accelerator pedal and your BMW will automatically turn into a truly dynamic performer. Offering a fast response and a far quicker gearshift, the new, thoroughly updated six-speed automatic transmission will also convince the driver with a particular penchant for sporting and active motoring. Quite simply because new torque converter technology gives the transmission a much more direct link to the engine responding immediately to the driver’s commands by shifting down quickly and directly one, two, three or even four gears in the interest of powerful and dynamic acceleration.

Precise choice of the optimum transmission ratio in each case ensures not only a significant improvement of driving dynamics, but also a substantial enhancement of economy compared with a conventional automatic transmission: Depending on the model, the six-speed automatic transmission serves to reduce fuel consumption in the EU cycle by up to 3 per cent on the gasoline engines and up to 6 per cent on the diesel models. And at the same time the new transmission is more compact and lighter than the five-speed automatic transmission used so far, thus contributing to the objective of EfficientDynamics in all areas.

Yet another feature contributing to an even more intense and exhilarating driving experience is a control function so far only available on BMW’s Sequential Manual Gearbox (SMG): Paddles on the steering wheel now allow the driver to intervene manually in the choice of gears at any time also on the new six-speed automatic transmission.

Five years after introduction of the world’s first six-speed automatic transmission in the BMW 7 Series, the premium car maker from Germany is once again setting the standard: Soon all BMW model series will be available with six-speed automatic transmissions, as an attractive alternative to the manual gearbox. And these innovative transmissions will not just be a comfort feature, but will also serve to enhance the car’s driving dynamics, since the six-speed automatic transmission ensures additional Sheer Driving Pleasure through its unique gearshift dynamics alone.

High-performance electric control for a fast response.
The new version of BMW six-speed automatic transmission allows a truly unique, active and sporting style of motoring. The sophisticated electronic control unit permanently monitors the position of the gas pedal, registering the intensity of the pressure exerted by the driver on the gas pedal and determining whether and to what extent the driver wishes to accelerate. Retrieving data on the road speed of the car, engine speed and the steering angle, the control unit also detects current driving conditions at all times, considering furthermore whether the car is driving uphill or downhill.

By taking all these criteria and many others into account, electronic transmission management, together with its high-performance software, is able to determine which gear is the most suitable under current driving conditions to meet the driver’s particular demands.

The driver expresses these demands smoothly, easily and clearly through his foot on the accelerator, the transmission control unit automatically choosing the topmost gear as long as the driver is just cruising along with consistent pressure on the gas pedal. In this case the automatic transmission will never forget to shift up, keeping the car in its most economical gear at all times. But at the same time the automatic transmission is always ready for any change in driving conditions, responding instantaneously and precisely to new demands and requirements, regardless of whether the driver wishes to slowly build up extra speed or whether he obviously wishes to accelerate fast and dynamically.

Direct choice of the optimum gear.
Whether the transmission should shift back and, if so, to what degree, is determined by the electronic control unit applying data provided on load and driving conditions as well as the rate at which the driver presses down the gas pedal. So depending on the overall scenario, the transmission is able to shift down in the same brief instant either “just” one or several gears. All that counts is how fast the driver wishes to accelerate. The harder he presses down the gas pedal, the more dynamically his car will accelerate to the desired speed, choosing the gear required directly and without any transitional phase.

This direct gear finding process, as it is called, gives the automatic transmission its unique precision, without any time-consuming search for the right gear, which the driver would always notice and experience as an unwanted delay. Indeed, the transmission will determine and find the optimum gear ratio instantaneously while the driver is still pressing down the gas pedal, making machine even faster than man.

A mere 100 milliseconds response time.
Responding at such unprecedented speed, BMW’s new six-speed automatic transmission sets new standards, the dynamic gearshift leaving behind not only conventional automatic transmissions, but even the manual gearbox: The new six-speed automatic transmission completes every gearshift process faster than even the vast majority of sporting drivers experienced in shifting gears manually. This is borne out particularly clearly by the extreme demand made by BMW’s development engineers in defining a kick-down signal at a speed of 70 km/h or 50 mph in sixth gear. The requirement even in this case is to ensure maximum acceleration – and precisely that is what the new six-speed automatic transmission provides, responding in just 100 milliseconds to the driver’s commands. At the same time the automatic transmission sends a positive force pulse to the engine, which immediately increases its speed from approximately 1,400 to more than 5,000 rpm while the transmission itself shifts back from sixth to second gear.

The time required for shifting gears is also shortened 50 per cent compared with a conventional transmission, again enabling the car to instantaneously switch over from a smooth cruising mode to fast and dynamic acceleration in less than a second, offering truly impressive shift-down performance quite impossible with any kind of conventional automatic transmission.

The new six-speed automatic transmission therefore responds more quickly than the driver is even able to notice – all he feels is the spontaneous reaction to his commands and wish for dynamic acceleration. And all that remains is a wonderful feeling of satisfaction, with the driver marvelling at the intuitive reaction of the new six-speed automatic transmission to his wish for dynamic performance.

New converter technology with reduced slip.
BMW’s new six-speed automatic transmission offers a truly unique experience of dynamic performance not only through its supreme spontaneity and precision, but also through its direct link to the engine. This provides an even more convincing, immediate thrill of engine power ensured by connecting the engine and automatic transmission to one another even more closely and directly than before. Indeed, this applies not only to the networked electronic management, but also to the mechanical link between the two units in the drivetrain: This is the new torque converter technology contributing directly to the supreme feeling of agile performance the driver will experience and enjoy at all times – especially as the new torque converter avoids any unnecessary slip, which would otherwise mean a loss in power, in nearly driving situations.

The converter lock-up clutch is closed immediately after setting off, connecting the six-speed automatic transmission directly to the engine and giving the power transmission the same character and feeling as on a car with a manual gearbox.

Two different technologies serve to avoid the transmission of torsional vibrations, thus setting off and compensating vibration within the engine itself: The gasoline engine models feature a turbine torsion damper harmoniously connecting the engine and the drivetrain, while the diesel engines come with a two-damper converter tailored to the particular characteristics of these power units.

One of the outstanding new qualities of the six-speed automatic transmission, as already described, is the ability to shift down up to four gears without the slightest loss of time. One of the prerequisites for this quality was further improvement of the hydraulic system, with the clutch required in each case being activated directly on the new automatic transmission to avoid any additional time otherwise needed in order to skip a gear. And to provide the computer power required for selecting the optimum driving gear in each case, BMW’s engineers have developed new software particularly demanding and sophisticated in its functions.

Apart from enhancing driving dynamics, all innovations also promote the efficiency of the drive system. A rapid gearshift also when shifting up, direct transition to the gear required, and the converter lock-up clutch operating with virtually no slip ensure far more economical motoring than with a conventional automatic transmission. The reduction of fuel consumption in the EU cycle by 3 per cent on the gasoline engine and 6 per cent on the diesel engine models is therefore by all means realistic also in everyday traffic, depending merely on the driver’s style of motoring. And with its compact dimensions coupled with low weight and a significant weight-saving as the final result, the six-speed automatic transmission meets yet another criterion for EfficientDynamics.

An important new feature for the active driver: gearshift paddles on the steering wheel.
Boasting a wide range of features to enhance the dynamic character of a BMW, the new six-speed automatic transmission becomes even more appealing, offering gearshift and response times even the skilled driver shifting gears manually will hardly be able to outperform. Still, the fact remains that particularly the sporting and ambitious driver will wish to enjoy a manual gearshift at least from time to time – and now BMW is also fulfilling this wish in a truly unusual manner.

The new models featuring BMW’s new automatic transmission come complete with gearshift paddles on the steering wheel, allowing the driver to shift gears sequentially by hand. Compared with the Steptronic gearshift previously offered in conjunction with the automatic transmission for a sequential gearshift by means of the selector lever on the centre console, this new option serves to enhance driving dynamics to an even higher level.

As a result, the driver is able to intervene manually into the gearshift function with greater spontaneity than ever before. Now, he is no longer required to move the selector lever in order to shift gears, but rather just has to push the paddles, showing the automatic transmission that he wishes to shift gears manually. At the touch of a button, therefore, the driver is able to shift up or down within split-seconds.

So far this manual gearshift function reminiscent of Formula 1 was to be found only in models featuring a Sequential Manual Gearbox (SMG), for example the extremely sporting and dynamic BMW M Cars.

2.7 More Efficient Use of the Flow of Energy: Intelligent Alternator Control and Recycling of Brake Energy.

The combustion engines featured in BMW’s current models offer a far higher level of efficiency than the drive units in former model generations, consuming less fuel while developing more power. Still, the fact remains that even today only about 25–30 per cent of the energy contained in fuel is actually converted into drive power on the road. By far the larger share, therefore, is converted into heat and is by no means used in full.

Another factor is that the generation of electric power for the car’s on-board network consumes an ever-increasing share of the power provided by the engine – which means that for this reason alone efficient energy flow management within the car is increasing in significance.

Developing Intelligent Alternator Control (IAC), BMW has established the prerequisites for even greater efficiency in the generation above all of electrical energy in the car thus used even more consistently. And in addition, the innovative on-board network also comprises a system to regenerate brake energy (Brake Energy Regeneration).

EfficientDynamics is ensured not only by maximum efficiency in the combustion process. Rather, it is essential to consider all energy flow conditions and their interaction in order to develop new solutions and concepts. Quite simply because a lot more takes place in a modern car between the actual process of ignition and the subsequent transmission of power to the road than the mere combustion of fuel in the engine.

Fuel combustion generates heat which, in a car fitted with turbochargers, is recycled from the exhaust emissions in order to boost engine output and which goes through heat exchangers to warm up the interior via the coolant system. A further point, as mentioned, is that a modern car requires a lot more electrical energy also derived, stored and used through the alternator and battery system.

This greater demand results from an increasing number of comfort functions, and also from new safety- and performance-relevant components such as chassis and suspension control, Active Steering, engine management and ABS. So applying an all-round concept of Intelligent Energy Management, BMW is working hard on making both the generation and use of energy as efficient as possible.

Already reality today: Intelligent management of the flow of energy.
In this process BMW Group engineers are pursuing two objectives: First, to limit the overall uptake of energy without making any concessions in terms of function. Second, to convert the energy in fuel into electrical energy in a smooth and efficient process minimising any losses in the overall energy balance.

BMW’s current models already fulfil important prerequisites for both of these improvements, with intelligent management of the flow of energy already being a “standard” feature in BMW’s production models. The new electrical coolant pumps on BMW’s straight-six power units, for example, operate on demand exactly according to current requirements, meaning that they reach their maximum level of performance only at high and very high speeds, while remaining passive, for example, immediately after the engine has started, thus allowing the engine to warm up more quickly. And since the coolant pump is driven electrically and is not connected to the engine, it does not withdraw any energy from the drive unit.

In all, this on-demand operation of the coolant pump improves fuel economy in the EU homologation test by approximately 2 per cent.

Over and above this superior technology, BMW has developed a further system of energy management permanently monitoring the current charge of the battery in an increasing number of BMW model series: The Intelligent Battery Sensor (IBS) ensures that the supply of electrical energy for starting the engine again is always sufficient, preventing any excessive demands on the supply of electricity and, as a result, any premature discharge of the battery. Following clearly defined priority management, this serves to reduce the supply of electric power for comfort functions such as the seat heating or air conditioning, maintaining enough energy at all times for safety-relevant functions and as a reserve for starting the engine the next time around.

Efficient management of power generation to prevent the loss of energy.
In future the time of energy conversion will also be carefully controlled in the interest of maximum efficiency. The main feature for this control function is Intelligent Alternator Control coordinating the management of energy flow as a function of driving conditions. This includes the regeneration of brake energy (Brake Energy Regeneration) and the supply of such energy into the car’s on-board network.

Intelligent Alternator Control or IAC uses components in the on-board network which, like the IBS, have already proven their merits in practice and are available throughout BMW’s entire range of models. And last but certainly not least, BMW will also introduce the other innovations into all model series at an early point in time, enabling as many customers as possible to benefit from these new technologies and generating a positive effect on overall fleet fuel consumption at the same time.

On a conventional car electrical energy is generated in all driving phases, the alternator (or generator as it is sometimes called) being driven permanently via a belt from the crankshaft.

In future this process is to be limited largely to phases in which the engine is not required to deliver drive power, that is in overrun and when applying the brakes. Accordingly, the driver will benefit from a greater share in the fuel energy serving specifically and exclusively to accelerate the car and provide ample drive power. While this is happening, the supply of power to the on-board network will be provided exclusively by the battery, the alternator only being re-activated when the engine moves into overrun or if battery charge is insufficient.

Brake Energy Regeneration: turning the brake system into a source of energy.
The objective of this development process is to generate electricity without requiring engine power and, accordingly, without using any of the energy contained in the fuel. Such “inexpensive” electric power is provided not only in the overrun mode via the alternator, but also through the recuperation of energy released while applying the brakes. Meaning that energy previously wasted as heat on the brake discs is also fed into the car’s on-board network.

This significantly reduces the need for generating energy while the engine is propelling the car, direct conversion of fuel into electrical energy being limited to just a few exceptional cases. Hence, Intelligent Alternator Control and Brake Energy Regeneration significantly enhance the efficiency of the engine and the overall economy of the car.

An important prerequisite for energy management linked directly to driving conditions is proper control and management of the battery charge, the battery being charged to only about 80 per cent of its capacity as long as the engine is propelling the car, depending in each case on ambient conditions. A reserve charge adequate for the consumption of power while the car is at a standstill and enabling the driver to start at any time is naturally maintained under all circumstances.

Battery charge exceeding this limit of approximately 80 per cent is generated only in overrun and while the driver is applying the brakes, that is with a favourable energy balance.

The energy generated in this way may then be used while the engine is driving the car, without requiring any activity on the part of the alternator. And since the number of charge cycles increases as a function of such precise management, BMW’s Intelligent Alternator Control is combined with modern AGM (absorbant glass mat) batteries able to handle far greater loads than conventional lead acid batteries: An AGM battery holds the acid content in micro-glass-fibre mats between the individual layers of lead, thus retaining its ability to store energy also when charged and discharged frequently and in many ongoing cycles.

Application of the brakes generates electric power, pressure on the gas pedal provides drive power.
On the road the use of Intelligent Alternator Control and Brake Energy Regeneration offers significant advantages: First, careful management of the electricity generation process helps to reduce fuel consumption in the EU homologation test by approximately 3 per cent. Second, the driver benefits directly from the alternator being disconnected whenever the engine is propelling the car, since this ensures more power for dynamic acceleration and superior performance. Again, therefore, EfficientDynamics means an improvement of both motoring economy and driving pleasure.

Intelligent management of electrical energy offers a significant potential for increasing the all-round economy of a modern car. The objective is to minimise any loss of energy, to enhance regeneration processes, and to upgrade mechanical conversion processes for the largest possible share of fuel energy being converted into dynamic performance on the road.

Each of these improvements is able by itself to reduce fuel consumption by a significant margin. Together, forming a perfect team, they ensure a higher level of driving dynamics than ever before. BMW’s overall concept of energy management therefore clearly indicates that future vehicle generations will offer significant progress in terms of EfficientDynamics. And with Intelligent Alternator Control as well as Brake Energy Regeneration being able to offer their advantages in all BMW models, the significant economical and ecological benefits provided in this way will become available without delay to a large number of customers.

3. BMW Materials Technology: Integrated Know-How from Research to Production.

3.1 Supreme Function the Light Way: Intelligent Development of Materials in Body and Engine Construction.

The BMW 5 Series is a genuine phenomenon: It is far more dynamic than its predecessor, it offers more space inside, and at the same time gives the customer a much wider range of comfort and safety features.

In one respect, however, the car has not grown. On the contrary: Depending on the specific model, the BMW 5 Series is up to 75 kilos or 165 lb lighter than its predecessor. This great achievement by our car development engineers in breaking through the weight spiral is attributable in particular to the specific use of modern materials with appropriate progress in the car’s concepts, construction and process technologies.

To make sure that the BMW Group is able to keep up this success in future, specialists in the Operating Strength and Materials Departments at BMW’s Research and Innovation Centre in Munich seek consistently, for each individual component, to find the best materials and develop the most appropriate production methods. This know-how they must demonstrate time and again, since there cannot be just one single material perfectly suited for every purpose and every model. Rather, the solution is to find an intelligent mix or blend of materials.

Focusing on the respective vehicle concept and its requirements, BMW Group specialists search consistently for the right material for each part and component. Where necessary, they also develop innovative materials combining different benefits with one another in an unprecedented manner. Ideally, each new material offers not only enhanced functions, but also maximum strength and load resistance, a long service life, and optimised weight.

Apart from the wish for extra comfort and more functions, legal requirements – for example in terms of safety or emission management – lead time and again to an increase in the weight of a modern vehicle. This again gives BMW another reason to counter the general trend towards larger and more attractive, but also heavier, cars through an intelligent design and engineering concept. And precisely this is why BMW combines enhanced dynamics with lower fuel consumption, lower emissions and lower weight. These, therefore, are the objectives underlying BMW’s development strategy of EfficientDynamics.

Using new materials, BMW Group specialists are able to reduce the weight of the car in nearly every respect. Highly developed metal alloys, for example, as we see on load-bearing elements made of high-strength and ultra-high-strength steel, are able to enhance the loads carried by specific components to the necessary level, while using far less material than before.

Even the fact that some particularly light metals, apart from their benefits, also have negative properties such as their sensitivity to water, does not stop the development process. On the contrary: Special production methods and unprecedented joining technologies are used to optimise the characteristics and features of the materials chosen. As an example, the lightweight brake discs on the new BMW 5 Series are made up of a grey cast iron friction ring and an inner aluminium cover. So while grey cast iron remains the material of first choice for the friction ring on account of its resistance to wear and thermal capacity, the use of aluminium on the inner cover serves to reduce weight at the same time. And the extra work involved in production also pays off, with lighter brake discs meaning less unsprung mass and, as a result, a considerable improvement in driving dynamics.

Influenced by the latest scientific findings and thorough practice-oriented research, the development of plastics and synthetic materials has also gained greater dynamism. Using upgraded material systems and process-optimised concepts, the number of options for working with plastics has increased significantly since the diversity of materials in this area is now much greater than before. Indeed, synthetic materials with features and properties tailored precisely to the requirements of the component to follow may now be developed for virtually every purpose and requirement.

Following the example of nature: optimum structures for optimum weight.
In their research and development activities, BMW’s specialists follow the example of nature time and again. Looking, for example, at the structure of plants or the configuration of a mammal’s or bird’s limbs used for movement, we see that evolution has created amazing blueprints for the efficient use of materials. And while such role models can never be copied directly one-to-one, they often serve as the benchmark and inspiration for innovations in technology.

It is therefore highly worthwhile to precisely analyse the surface structures of plants, the flexible configuration of bones or the concentration of materials at highly exposed points often perfected by nature, in this way gaining very helpful input for the development of new materials.

The hollow structure of the bones in a bird’s feather, for example, serves as a natural blueprint for the production of appropriate metal parts and components. Indeed, precisely this hollow structure has prompted BMW’s specialists to develop the inner high-pressure moulding process, where metal tubes are first bent to the desired shape and then placed in a moulding die. Subsequently a hydraulic fluid or air is pumped into the tube at both ends under high pressure, until the metal takes on the contours of the die.

This production technology allows the creation of components in geometrical shapes and dimensions, making optimum use of the space available and saving weight at the same time. So like the bones in a bird’s feather, components made through internal high-pressure moulding are robust, light, and flexible all in one.

Another principle carried over from nature is used in the production of the instrument panel for the new BMW 3 Series: This is the injection-casting integral foam process, with propellants being added to the molten plastic and, acting like yeast in a cake, releasing gas under high temperature.

To use this effect, the mould filled with molten plastic is opened to an exactly defined point once the surface of the component has cooled down and grown hard. In this process pressure within the core of the component still fluid at the time will drop and the gas is able to foam up the molten plastic. The final result is a reduction in weight on the instrument panel by approximately 20 per cent, as opposed to a conventional dashboard of the same size.

Unique: car underfloor cover with a wide range of functions.
Full coverage of the underfloor on the BMW 5 Series significantly improves the car’s aerodynamics. As a result, both air drag and lift forces have been reduced to a new level.

Another remarkable achievement is the material used for the underfloor cover: Low-weight reinforced thermoplastics (LWRT) are a special material created in a development process successfully reducing weight while maintaining at least the same standard of function to the benefit of the customer. Compared with the plastic covers used in the past, the new LWRT floor panels are approximately 30 per cent lighter, offer better acoustic properties, and protect the body of the car from water and stone-throw.

This new LWRT material is made up of two components: In a special process a core layer of glass-fibre-reinforced thermoplastics is covered on both sides by a thermoplastic film forming the flat semi-finished product in a pure sandwich structure. The second step is then to shape this semi-finished product under pressure and temperature into its final geometric contours, the material being pressed into a compact form around its edges and on the fastening points where the underfloor is bolted on to the body.

With the sandwich structure being maintained in all other areas, it helps to make the entire component extremely strong but flexible. And thanks to these flexible moulding and shaping properties on the semi-finished product, the final cover may be varied in its wall thickness and the geometry of the entire component designed for various requirements.

BMW is the only manufacturer in the world to use such a demanding, highly-advanced system of materials on the underfloor covers of its cars. The new LWRT material was developed especially for the underfloor cover on the BMW 5 Series and immediately won the SPE Award after making its debut in 2004, the “Oscar of the Plastics Industry” presented by the renowned Society of Plastic Engineers (SPE).

In the same year this new system of materials also received the German Innovation Award from the German Industrial Association of Reinforced Plastics. And today LWRT is also used on both the BMW 3 Series and 1 Series.

New structural foam forming strong compounds and connections.
More function, lower weight: Another example of how these two objectives are implemented through innovative materials is the body structure of the BMW 5 Series Touring, where integration of the Panorama Roof serves to optimise the overall structure of the vehicle around its A-, B- and C-pillars.

With this requirement presenting the specialists responsible for materials with new challenges, the objective in developing a new, appropriate material was to guarantee a high standard of dynamic body stiffness and at the same time optimise vibration comfort without increasing the weight of the vehicle. So instead of steel panels or thicker profiles, BMW now uses a newly developed, much lighter structural foam at this point.

This foam is injected into the body of the car during the body construction process, the structured foam elements then being able to expand during the painting process according to clearly defined standards and specifications and enhancing the dynamic stiffness of the car accordingly. In comparison with a conventional steel structure, the use of structural foam elements serves furthermore to reduce weight by approximately 10 kilos or 22 lb. And last but certainly not least, the new system of materials was integrated particularly quickly and efficiently in the existing production process, since no welding was required to fit the parts and components in position.

Plastic side panel for enhanced dynamics.
It is a fundamental rule at BMW not to use weight-optimised materials until they are at least equal in their functions and qualities to conventional materials. And the criteria applied for measuring such functions are both versatile and demanding, with the focus on both stability and a long service life as well as the looks and feel of the material, as perceived by the customer.

The properties of a new material usually also affect the production process and the design of the components involved. A perfect material must therefore allow flexible moulding and straightforward, unproblematic processing, offering high-quality results and maintaining these qualities also in the long term.

A good example of this superiority is the front side panel on the new BMW 3 Series Coupé made of plastic – to be precise an innovative thermoplastic material reducing the weight of the component by 50 per cent compared with a side panel made of steel.

This alone reduces the weight of the new 3 Series Coupé by approximately three kilos. And since this progress is achieved around the front axle, it benefits the car’s driving dynamics in full: Thanks to the light material used at the front, we see not only a reduction in the overall weight of the vehicle, but also an improvement of axle load distribution achieving an ideal ratio of 50 : 50 now made possible even more easily.

This changeover from steel to high-tech plastics has not had any effects on production, with the plastic side panels still being integrated online, that is directly, into the painting process, without requiring any special assembly procedures. Contrary to former plastic components, they no longer have to be painted separately and subsequently assembled. Rather, the new plastic panels are able to go through the normal painting process together with the overall body-in-white. And thanks to their high level of thermal resistance as well as their optimised longitudinal elongation and uptake of moisture, the side panels also provide the same looks and optical effects as conventional steel components after having been painted.

The new material also offers greater freedom in design, being easier to mould and shape than steel – an important factor giving the designer new freedom in the design process. Another major feature which has already offered significant customer benefits in the development of reversible bumpers is that the plastic side panels are largely resistant to minor bumps and impacts, the material returning to its original shape after minor deformation. Collisions at low speeds, for example when manoeuvring in a car park, therefore hardly leave any lasting traces behind.

Magnesium in engine production: BMW is No 1.
Magnesium is universally acknowledged as a high-tech material and as a symbol for progress in automotive engineering. But what is the real potential of this special metal?

Answering this question, the BMW Group’s material development specialists first weigh the pros and cons of various materials in a very simple and straightforward process: Magnesium must compete with steel, aluminium, and plastics. An obvious advantage is its low weight, with magnesium being approximately 60 per cent lighter than steel and 30 per cent lighter than aluminium. But when looking at flexural stiffness, mouldability, temperature resistance and anti-corrosion qualities, only new, truly innovative magnesium alloys are able to match steel and aluminium as major competitors.

The fundamental point, therefore, is to carefully consider which material is suitable on which component and for which application, especially as the prices of raw materials as well as complicated casting and production processes are at least initially a major obstruction to the use of magnesium on a large scale.

The overall conditions for using magnesium have however improved significantly in recent times, with this metal now being used, therefore, to a far greater extent than before. Both the seat frames and steering wheel rim, for example, are now made of cast magnesium, just as the instrument panel made of magnesium helps to significantly reduce the weight of the car.

BMW’s straight-six power unit is a particularly impressive example of how the use of magnesium can directly improve the standard of EfficientDynamics: Presented for the first time in the BMW 330i, this new power unit displacing 3.0 litres and developing maximum output of 195 kW/265 hp weighs just 161 kilos or 355 lb. And this is also because the crankcase on this straight-six is made of composite magnesium/aluminium.

The brand-new casting process developed for this process ensures an optimum bond of both metals, with magnesium also being used in the bedplate and on the cylinder head cover of BMW’s six-cylinder.

Together with further improvements, the introduction of the composite magnesium/aluminium crankcase serves to reduce weight by approximately 10 kilos or 22 lb versus the original straight-six power unit. And with this weight reduction being achieved at the front end of the car, we see another direct contribution to perfect axle load distribution and, accordingly, enhanced agility on the road.

Looking at future applications and developments, the BMW Group’s materials and vehicle development specialists are focusing on new magnesium alloys. A tempting application, for example, would be the use of magnesium above all on the chassis on suspension, significantly reducing unsprung masses in the process.

Making such concepts reality is a joint task of materials researchers, car makers, suppliers, and production engineers all acting together. And considering the wide range of experience already acquired as well as the Company’s high level of technical skills and competence, the BMW Group leads the way in this development process.