courtesy of wikipedia :
Just as the previous M3 generations all introduced a completely new engine, the fourth generation M3 did the same: the
BMW S65 engine was introduced. This S65B40 is a naturally aspirated, high revving 4-litre V8 (based on the S85B50 5-litre V10 that powers the E60/E61 M5 and the E63/E64 M6 to date) delivers 414 bhp (309 kW; 420 PS) at 8,300 rpm and peak torque is 400 N·m (295 lb·ft) at 3,900 rpm, which represents a power increase of 22% over the E46 M3. The engine weighs 15 kg (33 lb) less than the outgoing six cylinder for a total weight of 202 kg (445 lb). A six-speed manual transmission is standard. As from April 2008, BMW offers a new double-clutch gearbox, called M-DKG (Doppel-Kupplungs-Getriebe) or
M-DCT (Double Clutch Transmission) as an option, which reduces shift pauses to less than a tenth of a second and shortens the car's 0-100 km/h (62 mph) sprint time by 0.2 seconds vs. manual. It features both automatic and manual modes in a manner similar to the SMG gearboxes in the E36 and E46. The E92 M3 coupe inherits the carbon-fiber roof from the E46 CSL as part of the weight-saving program. For 2009, the E9x M3 received the same revisions as the non-M 3 series. The changes include revised front and rear bumpers, and LED tail lights.
The new M3 is once again available as a 4-door sedan, based on the E90 3-Series, but unlike the regular models, this car shares the coupe's front end, including headlights. However, it does not get the 2-door's carbon-fiber roof. The E93 hardtop convertible version joins the lineup shortly after the E92's launch, while an E91 wagon is due in the first quarter of 2009. A CSL lightweight version is heavily debated and longed for amongst car enthusiasts, and cars suspected to be the new M3 CSL have already been spotted at the famous Nordschleife (North Loop) of the
German Nürburgring.