Featuring a return to the inline-6 engine format made famous by BMW M, the all-new, 3.0-liter BMW M3 and M4 engine is approximately 10 kilograms lighter than its V-8 predecessor and packs an even stronger punch. With 425 horsepower from 5,500 — 7,300 rpm, 406 lb-ft of torque from 1,850 — 5,500 rpm, and capable of 0-60mph in 3.9 seconds when equipped with the M-DCT transmission

http://www.bmwblog.com/2013/12/12/bmw-m3-vs-bmw-m4-photo-comparison/