Mercedes-Benz has launched the ultimate sports utility vehicle, the ML55 AMG, which can outperform many sports cars.

The flagship 347 horsepower 5.5-litre lass accelerates from 0 to 62mph in a breathtaking 6.8 seconds and has a maximum speed of 145mph. Yet Mercedes-Benz says the 49,990 ML55 AMG retains the rugged off-road capabilities of all lass models.

Dermot Kelly, director of Mercedes-Benz passenger cars in the UK, said: "The ML55 AMG is a sensationally exciting product. It has enormous power and torque, which means that it is a formidable vehicle on and off the road.

"It is highly sophisticated and superbly equipped yet it is keenly priced. We have had a huge success in the UK with the lass and I am confident that this model will set a new benchmark in this important sector of the market."

Power comes from a 5.0-litre V8 from the Mercedes S-class, which is reworked by Mercedes-AMG. Aluminium pistons, special oil injector nozzles and high-performance camshafts are installed and the block is bored out to 5.5-litres capacity.

Huge 18in five-spoke alloy wheels are fitted and the Electronic Stability Program (ESP) and axle are modified to cope with the increased power.

Two power domes on the bonnet echo those of the Mercedes-Benz SLK roadster and unique AMG bodystyling and twin AMG chrome exhaust tailpipes add to the highly distinctive appearance.

Inside, the ML55 AMG offers sports seats trimmed in buffalo leather and black walnut wood trim, a finish unique to this car.

Distinctive ivory dials with chrome surrounds, a wood and leather trimmed steering wheel and gearshift and a leather-covered front armrest complete the special interior.

Xenon headlamps, which have a high-pressure cleaning system, are standard along with air-conditioning, electric front seats with memory settings, an electric glass sunroof, automatic dimming rear-view mirror, Bose sound system with seven speakers, a six-disc CD changer, heated front seats and automatic rain-sensing wipers.

Further developments have been made to the Mercedes off-road electronic traction system, 4-ETS, which will be added free to all lass models from October.

More than 10,000 lass models have been sold in the UK since they were introduced in September 1998.