The McLaren 650S is an evolution of the preceding MP4-12C and uses the findings gained from the Mclaren P1 in order to make the car more responsive and focused. It was initially designed to be offered alongside the 12C but the declining sales of the 12C prompted McLaren to market the 650S as its replacement. The 650 in the car's name refers to the engine's power output in Pferdest rke, the European standard for horsepower while the S stands for Sport. The powertrain of the 650S, the 3.8 L twin-turbocharged M838T V8, is largely carried over from the 12C but involves new pistons, better-flowing cylinder heads, new exhaust valves, and recalibrated camshaft timing.