Getting the M3 right is critical for BMW, because it's a sort of bellwether for the industry and enthusiasts alike--if a car is quick, it will inevitably be compared to the M3.
Getting the M4 right is even more critical for BMW, because it wears an all-new name over the bones and history of the M3 coupe. Committing any sins against its ancestors will be judged doubly for the M4.
Unfortunately, it's not yet clear just how good the new M duo is, but on paper at least, things are looking very good. As for how good it looks to the eyes of the aesthete, rather than those of the track dog, we'll let the images speak for themselves.
The new M3 sedan and M4 coupe are lighter and more powerful than their predecessors. A 3.0-liter in-line six-cylinder twin-turbocharged engine rated at 425 horsepower and 406 pound-feet of torque generates 3.9-second 0-60 mph acceleration when paired with the M-DCT dual-clutch transmission.
If you opt for the six-speed manual, that figure rises to 4.1 seconds--the price you pay for rowing your own gears, though you won't have to worry about rev-matching even if you pick the three-pedal 'box, as BMW has included automatic throttle-blipping. BMW hasn't yet clarified if the feature can be turned off.
Of course, BMW cautions that these power and acceleration specs are preliminary, and not yet certified for the U.S. market. So things may change--but we wouldn't expect them to change by much. The engine also sounds pretty great, as you can hear for yourself in the video above. We don't expect that to change at all.
As for that new S55 twin-turbo six, it's looking like a very enticing lump indeed. The peak power figure is nice, but unlike you find in a zingy, high-revving normally aspirated engine, the S55's peak power is available across a huge band of the rev rage: 5,500-7,300 rpm. That's peak power across the whole top third of the engine's range (the rev limiter kicks in at 7,600 rpm). Peak torque comes on early, at 1,800 rpm, and stays flat through 5,500-rpm.
2015 BMW M4Enlarge Photo
At the rear end, a new Active M Differential uses an electronically controlled multi-plate limited-slip unit to improve both traction and control; a similar setup is available in the new 2014 Chevrolet Corvette Stingray. With electronic control over the differential's engagement, anything from 0 to 100 percent lock can be achieved in milliseconds.
Top speed for the new M3 and M4 is electronically limited to 155 mph.
EPA gas mileage estimates are not yet available for the cars, but BMW says they'll be about 25 percent more efficient than the previous M3. That's a good thing, because the last M3 was rather thirsty, rating about 14 mpg city and 20 mpg highway. Using BMW's estimate as a rule of thumb, the new M3 and M4 could get as much as 18 mpg city and 25 mpg highway--still not particularly impressive figures, but a considerable improvement.