FOR Porsche purists an SUV model doesn't quite fit with the brand's image and a diesel version - perish the thought - is even worse.

But when you have a diesel SUV with a top speed of almost 165 miles per hour, which will hit 62mph in just 5.4 seconds and develops an enormous 859Nm of torque it's definitely earned the right to wear the coveted Porsche shield on its bonnet.

While actually no different in size to its predecessor the current model looks dramatically wider thanks to restyling and far more imposing because of the larger power dome on the bonnet.

Park it alongside most modern hatchbacks and they tend to look a little like Dinky toys in comparison.

But despite its bulk the Cayenne S more than lives up to the sporting pedigree of the German luxury car maker both in performance and handling.

Under the bonnet beats the heart of a massive 4.2-litre, twin-turbo V8 diesel which burbles wonderfully under normal driving conditions as only a V8 can and roars when you put your right foot down.

The massive torque means it's one of the most flexible power units I have driven making it wonderfully rewarding to live with and totally relaxing to drive.

The S uses an eight-speed Tiptronic S automatic gearbox which is seamless in operation and for everyday driving ensures that revs are always kept remarkably low. I managed to average just over 32 miles per gallon which is remarkable for a V8.

Inside the Cayenne S is just as dramatic as the outside with an aircraft-like number of switches and buttons.

In fact on the highly elevated transmission tunnel sitting between driver and front seat passenger there were no less than 35 with a further 13 on the overhead control panel.

Even the two front seats each come with six buttons so you can tailor-make your position and comfort to perfection.

One of the numerous nice things about this car is the flexibility given to the driver. You have the option of three suspension settings - comfort, sport and sport-plus- at the touch of a button and three modes of driving.

Switch from normal to Sport mode and you get shorter gear shifting times with a sporting driving style automatically recognised more quickly.

If you really want to push on with gusto change to Sport Plus and the transmission changes to a shift programme designed for driving on a racing circuit - but watch out for the blue light in your mirror. In this mode you really do have to keep a wary eye of the speedometer.

Drive goes to all four wheels with the Cayenne for supreme traction and there is a separate off-road switch for when you decide to take to the hills.

In addition you can engage Porsche Hill Control on or off-road which works between two and 20 miles per hour to automatically slow the car down by braking all four wheels.

Air suspension on the model tested (an additional £2,379) ensured a superb ride, visibly adjusting the height of the car when more people were travelling and ensuring you could corner the Cayenne S at speed with no body roll.

Passenger space in the Cayenne is huge with rear seat passengers getting limousine-like leg room. Boot space too is vast with 670 litres available with the rear seats in position and 1,728 litres with the split rear seat backs down.