Combined with the mechanical limited slip differential now fitted as standard to the rear axle Porsche says the new system will give the car better traction and stability. PTM works by feeding the right amount of engine torque in each situation through an electronically-controlled multiple-plate clutch to the front wheels, which in turn supplements the flow of power to the rear wheels.
With the previous viscous clutch, up to 40% of torque could be directed to the front axle. The new electronically-controlled PTM system delivers an infinitely variable torque split, and is able to distribute up to 100% of traction to the front or rear wheels.
The new Carrera 4 will also be available with Porsche PDK double-clutch gearbox as a £2,338 option. The second generation Porsche 911 Carrera 4 models go on sale in Great Britain on October 25.
The Carrera 4 Coupe 3.6-litre is priced from £67,430, and the Carrera 4S Coupe 3.8-litre is priced from £74,720. The 911 Carrera 4 Cabriolet is priced from £74,720, and the Carrera Cabriolet 4S from £82,010.