Auto Channel

Page 1: Introduction
Page 2: Concept
Page 3: Design
Page 4: Power Units
Page 5: Automatic Trans.
Page 6: Suspension
Page 7: All Wheel Drive
Page 8: Body & Safety
Page 9: Light Concept
Page 10: Features/Equipment
Page 11: Production
Page 12: History

Automatic Transmission

Fast, Responsive and Precise for Dynamic Driving Pleasure

• Reaction and shift times up to 50 per cent faster

• Six gears, direct selection of gears, maximum efficiency

• Innovative converter technology, high-performance software

All petrol and diesel versions of the new BMW 3 Series Coupé – with the exception of the 335d Coupé – come as standard with a six-speed manual gearbox. Despite the wide range of gear ratios between the lowest and highest gear, close increments between each gear enable the driver to shift smoothly and efficiently from one gear to another, maintaining engine speed at an optimum level. This guarantees both spontaneous and powerful acceleration as well as fuel economy optimised also at high speeds. The smooth and precise gearshift serves to facilitate a rapid change of gears in the interest of particularly dynamic acceleration.

Conveying engine power dynamically to the road.

The BMW 335d Coupé comes as standard with all-new six-speed automatic transmission optional on all the other models. More than ever before, this new transmission offers the high level of comfort rightly expected of such a transmission and ensures dynamic conversion of engine power into driving performance and motoring pleasure. An upgraded hydraulic system, an innovative torque converter, and significantly improved management software with a much higher level of performance not only ensure a more spontaneous response to every movement of the accelerator pedal, but also provide an extremely quick selection of gears.

As a result, reaction times of the automatic transmission in the new BMW 3 Series Coupé are down by approximately 40 per cent compared with conventional automatic transmission cars, with the actual gearshift times being almost halved. And thanks to direct transition to the appropriate gear level, shifting down by more than one gear does not take any longer than shifting just one gear. Last but certainly not least, the converter lock-up clutch remaining largely closed at most times ensures particularly dynamic development of power thanks to its direct connection to the engine.

The new version of BMW’s six-speed automatic transmission promotes a sporting and active style of motoring in a truly unique manner. This begins with the sophisticated electronic management system permanently monitoring the position of the accelerator pedal and registering how hard the driver is pressing down the pedal, determining in this way whether and how fast the driver wishes to accelerate. The control unit also monitors the car’s current driving conditions by checking out road speed, engine speed and steering angle data. Indeed, the system even considers whether the car is currently driving uphill or downhill.

Applying this wide range of criteria, the electronic control unit using high-performance software determines which gear is currently most appropriate in order to fulfil the driver’s requirements.

The driver expresses these requirements solely and exclusively through his foot on the accelerator pedal. When cruising along in relaxed style, with pressure on the gas pedal remaining consistent, the system always chooses the highest possible gear, ensuring that the BMW 3 Series Coupé maintains the highest level of fuel economy at all times. But at the same time the automatic transmission is always ready for any change in driving conditions, responding quickly and precisely to new demands and requirements, regardless of whether the driver is accelerating only gently or whether he pushes down the accelerator pedal quickly and with full force for really fast and dynamic acceleration.

Finding the right gear immediately.

Applying data on load and driving conditions and comparing these parameters with the forces acting on the gas pedal, the electronic control unit determines whether and to what extent the transmission should shift down to a lower gear. So depending on overall driving and engine load conditions, the transmission is able to shift back just as quickly either by one or several gears. The only criterion is how quickly the driver wishes to accelerate. The harder the driver presses down the gas pedal, the more dynamically the transmission will accelerate the car, immediately choosing the right gear for optimum acceleration.

This direct gear choice, as it is called, gives the automatic transmission its unique precision, without the need to look for the right gear in a time-consuming process possibly irritating the driver. Indeed, the transmission already determines the optimum gear while the accelerator pedal is still pressed fully down.

Reaction time shortened to 100 milliseconds.

The new six-speed automatic transmission in the BMW 3 Series Coupé sets new standards in terms of fast reaction. This exceptionally dynamic gearshift is borne out most clearly and impressively by the extreme requirement made by BMW’s development engineers applying a kickdown signal at a road speed of 70 km/h or 50 mph in sixth gear. Even under these circumstances, BMW expects the car to offer maximum acceleration – and precisely this is ensured immediately and spontaneously by the new automatic transmission reacting to the driver’s commands in just 100 milliseconds. At the same time the transmission sends a positive power signal to the engine immediately revving up from approximately 1,400 to more than 5,000 rpm while the transmission shifts down just as quickly from sixth to second gear.

Shift times have also been halved compared with all conventional transmissions. In all, therefore, the car switches from a comfortable cruising mode to powerful acceleration within less than a second, offering supreme downshift performance quite impossible in the past with a commercially available automatic transmission.

Through its reaction times alone, the six-speed automatic transmission enters new dimensions the driver can hardly even perceive. All he feels, therefore, is the spontaneous response to his commands and the immediate acceleration of the car. And what remains in his mind is the superiority of the new six-speed automatic transmission in immediately providing supreme power and performance.

Directly connected to the engine.

The new six-speed automatic transmission in the BMW 3 Series Coupé offers an unusually dynamic driving experience – not just through its supreme spontaneity and precision, but also through its direct connection to the engine providing an even more direct feeling of the engine’s power and performance.

To ensure this effect, the engine and automatic transmission communicate with one another more intensely than ever before. This direct contact is provided not only by electronic management and control, but also by the mechanical link joining the two units. The superior feeling of agility, in turn, results from new torque converter technology, the new torque converter avoiding unnecessary slip leading to a loss of power in nearly all driving situations.

The new torque converter is locked up immediately after the car has set off, six-speed automatic transmission thus providing a direct connection to the engine and giving the driver the same impression as with a manual gearbox ensuring a direct flow of power. Transmission of torsional vibration is prevented by two different technologies in order to set off any such transmission within the engine: The petrol engine versions of the BMW 3 Series Coupé feature a turbine torsion damper providing a harmonious connection between the engine and the drivetrain. The diesel engine in the BMW 330d Coupé, in turn, comes with a double-damper converter geared to the specific features and characteristics of this special power unit.

New software for an even faster gearshift.

One of the particular qualities of the new six-speed automatic transmission is its ability to shift down up to four gears without the slightest loss of time. To achieve this rapid and spontaneous performance, the hydraulic system had to be upgraded to an even higher standard, the clutch required in each case being directly activated in the new automatic transmission of the BMW 3 Series Coupé. As a result, no additional time is required to “skipâ€Â' a gear in the process of shifting up or down.

New, particularly sophisticated and functional software has been developed in order to provide the computer capacity required for choosing the optimum gear in each case.

Apart from improving the car’s driving dynamics, all the innovations now introduced also enhance the efficiency of the drive system as a whole. A fast gearshift when shifting up, direct selection of the appropriate gear and the almost complete absence of slip in the converter lock-up clutch provide advantages in fuel economy clearly noticeable also in everyday traffic. And through its compact and light construction together with lower weight, the six-speed automatic transmission fulfils yet another criterion for efficient dynamics.

Offering qualities highly conducive to the dynamic character of the BMW 3 Series Coupé, the six-speed automatic transmission provides significantly greater strength and benefits than ever before. It allows
gearshift and reaction times even the most skilled driver with lots of experience in shifting gears manually will hardly ever outperform. Still, the fact remains that particularly the sporting and ambitious driver often wishes to shift gears by hand and keep everything under manual control.

Ready-to-go at all times: gearshift paddles on the steering wheel.

Whenever the driver wishes to control the sporting character of the power transmission himself, all he has to do in the new BMW 3 Series Coupé is to choose gears by means of paddles on the steering wheel. These paddles allow a particularly active style of motoring, with the driver shifting gears by hand and in a sequential process. The driver is therefore able to move from one gear to another very spontaneously, directly activating the paddles whenever he wishes as long as the selector lever is in position D.

Short response times significantly enhance the sheer pleasure of active motoring – and at the same time the position of the paddles on the steering wheel serve to enhance the car’s standard of safety, allowing the driver to keep both hands on the steering wheel also when shifting manually. Clearly, this enables the driver to concentrate fully on driving conditions and the traffic around him, focusing precisely on the course he is following and the optimum choice of gears.

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