PORSCHE is celebrating 40 years of the iconic 911 Turbo with a pair of new versions that combine the virtues of a circuit racer with those of an everyday road car

The new Type 911 generation Turbo and Turbo S models will arrive in September and cost from £118,349 and £140,852.

They feature a new all-wheel drive lightweight chassis with active rear axle steering, adaptive aerodynamics, full-LED headlights and up to a whopping 560bhp from the twin-turbocharged 3.8-litre engine.

A 100mm longer wheelbase, riding on larger diameter 20-inch wheels, plus the Porsche Dynamic Chassis Control active anti-roll system - offered for the first time on the 911 Turbo models - increases the dynamic performance potential even more.

This system is included equipment on the 911 Turbo S, along with the Sport Chrono Package Plus and ceramic composite brakes that are options on the standard 911 Turbo.

As a result, the Turbo S has trimmed the benchmark lap time around the famous Nurburgring-Nordschleife circuit to well under 7mins 30secs - on standard production tyres.

Power - 520bhp in the Turbo and 560bhp in the S - is transferred to the drivetrain via a seven-speed dual-clutch PDK transmission with auto start/stop that now activates earlier when coasting to a halt.

Together with a new thermal management system for the turbo engine, Porsche has been able to cut the average fuel consumption of both models by 16 per cent to 29.1mpg.

That's from a 911 Turbo capable of accelerating from 0-62mph in a fleeting 3.2 seconds while the Turbo S is quicker still at 3.1 seconds. Top speed is 197mph.

Inside, the Turbo S offers an exclusive Black/Carrera Red colour combination and Sport Seats Plus with 18-way adjustment and position memory.

The seat backrest shells are also leather upholstered and a Bose Surround Sound audio system is standard. New options include a radar-controlled cruise control system, camera-based road sign recognition and speed limit recognition.