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The M double-clutch transmission - page 7 / 21





7 / 21

BMW Media Information

1/2008 Page 7

Electronic transmission management recognising the driver’s particular preferences. In choosing the gear to be prepared for operation, the electronic control unit naturally takes current driving conditions – that is the current situation on the road – into account: Focusing on the position of the gas pedal, engine speed, road speed and the driving program currently in use, the system recognises the kind of acceleration the driver wishes to enjoy or, conversely, whether he wishes to reduce his speed on the road.

Operating in such an intelligent manner, the transmission control consistently makes the necessary preparations for harmoniously continuing a manoeuvre initiated by the driver. So even with an extreme change in the style of motoring, the system changes gears appropriately, again at unparalleled speed and with unparalleled precision. Should the driver be required to suddenly stop the process of acceleration, for example, the M double-clutch transmission will promptly provide the transmission ratio required under such new conditions, operating just as quickly and efficiently as a conventional automatic trans- mission of the latest generation set to an extremely dynamic gearshift mode.

A two-mass flywheel serves as the torsion damper and the two clutches are activated via an integrated hydraulic module. Dry sump lubrication, in turn, guarantees a high standard of reliability and maintenance-free function throughout the entire running life of the car.

Special cooling to handle even the most extreme conditions. The engineers at BMW M GmbH have adapted the M double-clutch trans- mission with Drivelogic not only to the high engine speed concept and the specific torque curve of BMW’s M engines, but also to the high thermal loads encountered in the drivetrain of such a high-performance sports car. As an example, the transmission fluid is kept within the optimum temperature range not only by integrating the transmission into the coolant cycle of the engine. Instead, an additional oil/air cooler helps to avoid excessively high temperatures inside the M double-clutch transmission even under extreme conditions, for example on the race track.

A further point is that the transmission fluid, being connected to the engine’s cooling system, reaches its normal operating temperature faster than usual, for example in particularly cold weather. This again helps to reduce frictional losses in the warm-up phase and saves fuel in the process.

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