The E92 is powered by a 4.0 liter V8 engine derived from the V10 engine used by the E63 M6 and E60 M5. It reuses an optimized variant of the E46's limited-slip differential that is capable of 100% lockup. It also had various weight saving techniques applied, including a carbon fiber roof, and introduced a 7-speed M-DCT dual-clutch automatic transmission.