With the release of the BMW V8 M3 convertible also came the release of BMW’s new M double-clutch transmission with Drivelogic.
BMW claims that the new transmission providces faster and smoother shifting and even more fuel economy and when you see the figures released for the V8 M3 then it’s hard not to believe those claims.
The new transmission offers as many as eleven driver-selectable electronically controlled driving program choices. These include five shift programs in the fully automatic mode and six in manual mode, and are supplemented by a selectable Launch Control program that provides blistering off-the-line acceleration where the power from the 309 kW, 4.0-litre V8 M3 engine is transferred with maximum effect to the road.
The heart of the new BMW transmission is the double clutch system that acts to smooth out gearshifts to the point that they are often only discernible by watching the rise and fall of engine rpm on the M3’s tachometer.
Each oil-cooled wet clutch activates its own set of ratios – one is used for first, third, fifth and seventh gears, as well as reverse, while the other looks after second, fourth and sixth gears.
Gearshifts are effected by the disengagement of one clutch and the engagement of the other, moving seamlessly from the ratio in use to the next, preselected ratio. The fact that the next ratio is preselected and engaged merely by activation of the clutch is the secret behind the smooth and efficient transition from gear to gear.
The new M double-clutch transmission also incorporates a Low Speed Assistant mode that operates when manoeuvring at speeds less than 5 km/h to significantly increase the smoothness and degree of accelerator control available to the driver.
Gradient detection also means that the new M double-clutch transmission with Drivelogic is able to determine the appropriate ratios when travelling up or down hills.
This avoids the “hunting” between gears so often experienced in regular automatics when travelling on undulating roads, while the appropriate selection of lower gears on downhill gradients helps maintain road speed by using the braking power of the engine.
In fully automatic D mode, the driver can select from five Drivelogic programmes that regulate both the gearshift speeds and the change points right through to the D5 mode where the engine is stretched close to its maximum rpm – depending on throttle position – on upshifts. In D1 mode, the M3 with M double-clutch transmission is able to start off in second gear to help avoid wheelspin in slippery conditions.
In manual mode, six different Drivelogic programmes allow a similar range of characteristics, with the added driver control provided by the ability to choose shift points manually. In S6 mode, the drive can also activate launch control by holding the shift lever in the forward position.