 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 "Pferdestärke", the European standard for horsepower while the S stands for Sport.Most of the components are carried over from the 12C which includes the carbon-fibre monocoque chassis which has aluminium subframes front and aft.