The Porsche 911 Carrera 4S and the Audi R8 have long been rivals, and now it’s time for the latest version of the all-wheel-drive models to go into battle. The 2012 Porsche 911 Carrera 4S is powered by a 3.8-litre 6-cylinder engine that develops 400 hp and it's capable of taking it from zero to 62 mph (100 km/h) in 4.1 seconds. On the other side, the 2013 Audi R8 has a 4.2-liter V8 engine that's good for 430 hp and it needs 4.3 seconds to reach 62 mph (100 km/h).