The fourth generation M5 features a 507-hp V10 engine and 7-speed SMG transmission. BMW claims that this will give the M5 the best power-to-weight ratio in its class. Coupled to a SMG system that is 20% faster, BMW makes a very credible claim of sub-5-second 0-60 times. While the interior receives a host of M-exclusive appointments, the exterior provides only a few modest hints at the M5's performance potential.