DIESEL would once have been a dirty word as far as Porsche is concerned and though it remains inconceivable a diesel engine would ever be installed in a 911, for a car like the Cayenne it makes perfect sense.

The Cayenne has always had its detractors, mostly Porsche purists who held no truck with the fact a legendary sportscar maker like Porsche would even think of building an SUV, never mind going ahead and actually doing it.

Then there were those who lambasted it as ‘ugly', though to be fair the intention was never to win any beauty contests.

Meanwhile Porsche was laughing all the way to the bank as the Cayenne became the best-selling car in its history and propelled profits into the stratosphere.

Though the looks were altered as part of a hefty mid-life makeover for the original model this year saw the launch of an all-new Cayenne.

It certainly looks the part and clearly a great deal of effort has gone into making an SUV that actually looks like a Porsche this time round.

It's most noticeable in the curvaceous and stylishly-sculpted front end that has more than a hint of the 911 about it. There's a definite bit of design DNA going on and in this case the designers really have managed to pull it off - it would have been easy for it to have ended up looking like a bit of a dog's dinner.

A sporty SUV profile is completed by lines that flow up from the bonnet and finish in a nicely rounded rear end.

If the exterior looks are a success then the interior is a revelation.

Here the classy cockpit styling seen in the four-seat Panamera has been utilised to great effect.

Compared to the old Cayenne the instrumentation and switchgear is simply light years ahead with a combination of style and sophistication it's hard to see dating.

The 3.0-litre diesel engine sourced from Audi made its debut in the last generation Cayenne late on in the model cycle and remains pretty much unchanged in the latest version.

It feels pretty good in the Cayenne, delivering 240bhp and an impressive 550Nm of torque.

As with the previous model it is exceptionally well insulated to keep noise at a minimum and the engineers have even managed to come up with a relatively decent engine note.

Performance is impressive, more so at low speeds than higher ones and though this diesel Cayenne isn't in the same league as the petrol-powered ‘S' or ‘Turbo' models I reckon it's a worthy wearer of the Porsche badge.

Of course the big payback is economy. A combined cycle return of just under 40mpg has to be a major selling point and is also a significant improvement on a figure of around 30mpg for the old model.

The latest Cayenne handles even better than its predecessor too, with a light and nimble feel and minimal roll when cornering at speed. It definitely has an authentic sporty feel.

A new extended wheelbase also means there's more room in the cabin, something the old model was definitely lacking.

The latest diesel comes with a new eight-speed automatic gearbox as standard. Porsche say the spread of ratios is sufficient for off-roading without the need for a separate low-ratio gearbox, a factor which helps keep the weight down, thus enhancing both performance and economy.