2018 Porsche 911 GT2 RS - The engine has been lifted from the Turbo S, but the 3.8-litre twin-turbo flat six’s power output has been bumped from 580 to a staggering 700 horsepower at 7000 rpm, thanks in part to the fitting of larger turbochargers and a revised air intake. Maximum torque is rated at 553 pound-feet, and all of it is available from a low threshold of 2500 rpm. The GT2 RS is rear-wheel drive and the only gearbox available is the dual-clutch, seven-speed PDK.