Road Test: Porsche Cayenne S Diesel 5dr Tiptronic S

Normally, Porsche need only change the paint colour on its brake calipers, and it's on every car magazine cover. But here we are with a brand-new high-performance engine in Porsche's biggest-selling model, and no one much is batting an eyelid. Here's why. This new V8 Cayenne S Diesel came out in the same month as the Range Rover, so all eyes were elsewhere. They were missing something good.

One sentence shows why. It has a twin-turbo V8 with 382bhp and 627lb ft of torque, and gets itself to 62mph in 5.7secs. Yet it still has pretty reasonable fuel consumption. It actually weighs less than the aluminium-bodied Range Rover, because it's smaller and doesn't have so much off-road gubbins. But if you fit all-season tyres on the sensible 18in wheels and go for air suspension, it won't disgrace itself when you've off-roadin' to do.

But, as a Porsche, it's got to be a happy road car, and it is. This is one mighty engine. It's derived from the Audi twin-turbo diesel V8, but Porsche has pushed the output further. The pistons, valves and intercoolers are renewed. It wasn't just the power and torque they bothered about, either. It takes more than mere accident to have a diesel sounding like a petrol V8: it took work. Aurally, it's more Dick Petty than John Deere.

Acceleration is never viciously quick, but it's always insistently strong, and having eight ratios in the auto 'box means there's normally the right one for your purpose.

In other ways, this is a standard 2nd-gen Cayenne. The steering is precise, the body motions well controlled, the agility surprising, and the ride perfectly satisfactory. The cabin wraps itself around you as a driver, rather than fielding the airy openness of a Range Rover. But five can get in without being cramped, and the boot's vast.

It's also, by Porsche standards, a lot for the money. The £58k price comfortably undercuts a V6 petrol Panamera 4, even if you add air suspension and nav. The kicker is affording to fill the 100-litre fuel tank, but at least it'll take you a long way.