2011 Porsche 911 GT3 RS 4.0

The 911 GT3 RS 4.0, launched in 2011, was the final evolution of the 997 GT3 and featured a 4.0 litre flat-six engine (the largest engine offered in a street-legal 911). The engine itself uses the crankshaft from the RSR with increased stroke dimensions (from 76.4 mm to 80.4 mm). This change has increased the power to 368 kW (500 PS; 493 hp) at 8250 rpm and 460 N·m (339 lbf·ft) of torque at 5750 rpm. Chassis development has been influenced by the GT2 RS and uses parts from other RS 911s. Front dive planes give additional downforce up front. The car weighs in at 1,370 kilograms (3,020 lb), giving it a power-to-weight ratio of 365 bhp per ton. Only 600 cars were built. At 493 hp (368 kW),[18] the engine is one of the most powerful six-cylinder naturally aspirated engines in any production car with a 123.25 hp (92 kW) per litre output.