Since the current Range Rover was launched in 2002, Land Rover has been hard at work ridding it of its original BMW componentry, replacing the hardware with items from the Ford global parts bin. The new supercharged model therefore not only gets a blown 4.2-litre V8 engine, it's also the recipient of a general mid-life revamp that covers the rest of the range as well.

Jaguar's parts store has been plundered the most, supplying both new petrol V8s - a normally aspirated 4.4-litre producing 301bhp, and a derivative of this engine sleeved-down to 4.2 litres and supercharged to develop 389bhp. (The BMW 3-litre turbodiesel continues until the new Ford V8 turbodiesel arrives 12 months from now.)

On the face of it, then, we now have two performance-orientated supercharged V8-engined Range Rovers. But despite the on-paper similarities with the Sport, the two machines are very different to drive.

As part of the revamp, Land Rover has improved the on-road dynamics of its flagship, sending in Mike Cross (Jaguar's chassis guru) to work his magic. The result is changes to dampers, bushes and steering rack, together with a programmed ECU for the air suspension. What hasn't been added, though, is the anti-roll technology from the Range Rover Sport - the Range Rover's priority is now deemed to be pure luxury, with speed through corners of secondary importance.

Land Rover design director Geoff Upex was given the task of tidying up the exterior of the Range Rover, as well as creating a way of differentiating the supercharged car from lesser models. All Range Rovers get a fresh front grille and headlights; the supercharged model has a perforated version of the grille, this design theme echoed in the side vents. The rear treatment looks less successful, though, with the twin chrome exhaust pipes that dangle below the rear bumper seeming an afterthought.

Inside gets an even milder revamp, just ventilated leather for the seats, aluminium pedals, and the option of a gloss black finish for the interior wood.

On the move, it's business as usual; the Range Rover still feels a big car to punt around. The effect of the chassis changes is a general improvement to the dynamics with no single aspect standing out. Steering response goes up a notch for example, especially either side of dead-ahead, but you'd need to drive the new car back-to-back with the previous version to really tell.

Yet on the twisting, high-speed motorway at the start of our Spanish test route, you could definitely feel the benefits of Mr Cross's chassis honing. The Range Rover now gives you a new-found confidence that it's OK with spirited driving, despite rolling dramatically on its relatively soft air springs - the big off-roader no longer lowers itself at motorway speeds, thus giving more suspension travel and a more comfortable ride when travelling quickly.

Even with a 389bhp supercharged V8 to push this posh breeze-block along, and the promise of a 7sec dash to 60mph, the Range Rover soon runs out of puff at high speed. And our test average of 11mpg also revealed a slight drinking problem.

So it might be worth trying the normally aspirated V8, which gave a more lively account of itself than I was expecting, thanks perhaps to its lower overall gearing compared with the top model. And it's also noticeably quicker than the equivalent outgoing model.

This latest Range Rover leaves you in no doubt that its role is to pamper its occupants; it's one of those cars where travelling in the back seats is just as enjoyable as sitting up front. That's because the arrival of its dynamically accomplished smaller brother, the Range Rover Sport, leaves the Range Rover Proper free to get on with what it does best, being the ultimate luxury SUV.