Porsche is to launch the latest four-wheel drive versions of the 911 sports coupe in October.

The new models are 44 millimetres wider over the rear fenders so the rear wheels of the Carrera 4 can be fitted with 295/35 ZR 18 tyres, and the Carrera 4S with 305/30 ZR 19 tyres. The Carrera 4 has a 3.6-litre six-cylinder engine, with output of 239 kW (325 bhp), and accelerates from 0 to 100 km/h in 5.1 seconds and has a top speed of 280km/h. The 4S model, with 261kW 3.8-litre engine, can reach 100 km/h in 4.8 seconds and has a top speed of 288 km/h.

The all-wheel drive system has a multi-disc viscous coupling and transfers between five and 40% of the tractive force permanently to the front wheels.

Porsche Stability Management (PSM) now has two new functions: the brake system is pre-filled ready for a full brake application, thus eliminating the air gap between the pads and the disc and making stopping distances even shorter.

The second new PSM function is activated if the driver depresses the brake pedal quickly but not forcefully. In this situation, the hydraulic pump builds up extra pressure to bring all the wheels into the ABS range and ensure optimal braking.

In its regular setting, Porsche Active Suspension Management (PASM) offers a sporty but comfortable basic shock absorber setup, but operation of the sport button activates a noticeably firmer mapped setting. In both settings, however, the suspension ratings are matched at all times to the driving style and road conditions. The active shock absorber system is a standard feature on the 911 Carrera 4S and an optional extra on the Carrera 4. Both models can optionally be fitted with sports suspension to lower the body 20 millimetres closer to the ground; this includes a mechanical rear axle differential lock.

The optional Sport Chrono Plus package is also available for the new all-wheel-drive models. It modifies the engine management characteristics and the control behaviour of the PSM and PASM systems.

The two models will be launched in Germany on October 22, 2005.