Porsche has just unveiled the new 991 generation 911 Turbo (above, right) and Turbo S (above, left), bringing with it increased power and an all new lightweight chassis with a 100mm longer wheelbase and larger 20-inch wheels.

The Turbo S features Porsche Dynamic Chassis Control (PDCC) - an active anti-roll system that increases the dynamic performance bundled together with the Sport Chrono Package Plus incorporating dynamic engine mounts, and Porsche Ceramic Composite Brakes (PCCB).

These are offered on the 911 Turbo as well, as optional extras.

Occupants will feel the need for speed with the standard fitted 'sound symposer' - which channels induction sounds of the turbo engine to the passenger compartment via the speakers.

The turbocharged 3.8-litre flat-six produces 520bhp in the Turbo, and 560bhp in the Turbo S. All that power is transferred to the tarmac via a seven-speed dual-clutch transmission (PDK), which enables an auto start/stop function with an engine shut-off that coasts the car to a halt. Tweaked engineering and better thermal management have reduced fuel consumption rates by up to 16 percent to 12.3km/L including the Turbo S.

A newly developed water cooled all-wheel drive system (PTM) provides faster and more precise power distribution to the two axles, via an electronically controlled and activated multi-plate clutch.

When the 911 Turbo is equipped with the optional Sport Chrono Package Plus the car accelerates from nought to hundred in a brisk 3.2 seconds - 0.1 second slower than the Turbo S before reaching a top speed of 317km/h.

The 911 Turbo models incorporates rear axle steering through two electro-mechanical actuators on both sides of the car. The steering angle of the rear wheels can be varied by up to 2.8 degrees, depending on vehicle speed.

At speeds up to 50km/h, the system steers the rear wheels in the opposite direction to the front - which virtually shortens the wheelbase by 250mm, while at speeds above 80km/h, the system steers the rear wheels parallel to the front wheels - which virtually lengthens the wheelbase by 500mm.

The interior builds on the styling themes of the 911 Carrera family. The Turbo S offers an exclusive Black/Carrera Red colour combination and Sport Seats Plus with 18-way adjustment and position memory. As with its predecessor, a Bose Surround Sound audio system is standard with a higher output Burmester unit available as an option. A radar-controlled cruise control system, camera-based road sign recognition and speed limit recognition are other options on offer.