Volvo, it seems, takes exception to the maxim that you don't mess with a winning formula. The XC90 has been the Swedish company's biggest recent success, with demand way outstripping supply, but it's also a product that debuted in 2002, aeons ago in the motoring world. Since that time, we've seen all manner of new entrants in the luxury 4x4 market and Volvo has tinkered with the basic package in an attempt to keep the XC90 fresh. It was only a matter of time before the XC90 needed some rather more serious surgery and rather than let sales tail off, Volvo has stepped in and applied the changes. The latest car looks like an XC90 but there are wide-ranging alterations.

Let's start with that subtly-modified styling. The exterior design of the XC90 has long been one of its strong points. It's imposing without ascribing to the neo-brutalist school of vehicle architecture popularised by the likes of the Land Rover Discovery and Jeep's Commander. Instead, it mixes slab sides with smooth curves in a way that's beautifully resolved. It's recognisably a Volvo yet remains one of the best looking 4x4s money can buy.

The latest car emphasises the curves of the XC90's 'shoulders' with a redesigned tail light section. There's also additional chrome detailing, a full-width rear scuff plate and a bumper that incorporates a little more body colouring to visually lower the rear of the car. The front also adds a splash more chrome and colour-coding while revised 18-inch alloy wheels and colour-coding for the side mouldings, mirrors and door handles give the flanks a cleaner look. Volvo is also offering a palette of more modern exterior colours including a very striking White Pearl finish.

The interior has been given a makeover too with the aim of giving the XC90 a more luxurious, premium feel. The cabin was already extremely good in terms of functionality and ergonomics, if lacking a certain elegance that buyers in this market have increasingly come to expect. That's fixed now. New materials and upholsteries including opulent Sovereign Hide soft leather, Sapele wood trims and aluminium detailing are all on offer to shunt the XC90 that little but further upmarket. An RTI satellite navigation system that works from a hard disk rather than a DVD is true next generation technology, it's also quicker and easier to use than previous Volvo systems.

"The XC90 sales curve just doesn't incorporate dips"

The stereo system too follows a decidedly contemporary bent with an auxiliary input for your MP3 player. The standard High Performance unit will play CDs with music in MP3 and WMA formats as well. Opt for the Premium Sound audio package and you'll get a digital class D amplifier from Alpine with ICE Power technology from Bang and Olufsen Powerhouse, Dolby Pro Logic II surround sound and Dynaudio loudspeakers. Active bi-xenon headlamps move up to 15 degrees from the straight ahead when you're negotiating corners, the system automatically disabling itself during daylight hours. A wide angle park assist camera is also available.

The big news is a revision in the engine line up. The 183bhp D5 diesel continues with its muscular 400Nm torque rating but the petrol 272bhp six-cylinder T6 and the 210bhp five-cylinder 2.5-litre turbo engine have both been quietly shelved. In their place come a pair of engines that are massively more appealing. The entry-level petrol unit is now a 236bhp 3.2-litre straight six powerplant, built at Bridgend in Wales. Largely constructed of aluminium, this lightweight yet punchy engine is smaller than the old five-cylinder lump and thanks to Variable Cam Timing and Cam Profile Switching, it's a good deal more efficient. The 0-60mph sprint takes 8.9s and the official combined economy figure is 23.9mpg.

Volvo has also unleashed a big hitter in the form of a 311bhp 4.4-litre V8 engine. Their first V8, this is the same powerplant that's offered in the S80 V8 AWD and it's something rather special. Its narrow V-configuration means that it's possible - as with all Volvo engines - for it to be mounted transversely and still offer excellent crash protection space in the front crumple zone. With the block and the head cast in aluminium, this engine weighs in at just 190kg. Low weight means better handling, sharper acceleration, improved fuel economy and lower emissions.

While it may seem a little counter to Volvo's tree-hugging image to sell a brash V8 'SUV', this XC90 has a social conscience of sorts. One of the cleanest V8 engines on general release, it meets stringent American ULEV II (Ultra Low Emission Vehicles II) standards thanks to four catalytic converters, a lean air/fuel mix for cold starting and a higher idling speed at cold start. Volvo's engineers had identified that the first 15-20 seconds after starting was when the majority of harmful emissions were created and have worked to quell this occurrence. That's the environmental bit out of the way. If you're a little less concerned about polar ice caps, you'll be pleased to know that a heavy right boot will send the XC90 V8 to 60mph form standstill in under seven seconds with a hefty 440Nm of torque chiming in nicely at 3,900rpm.

Safety is another prime Volvo strength. Parent company Ford were, after the Explorer/ Firestone debacle, glad to hear that the XC90's innovative Roll Stability Control (RSC) system received the World Traffic Safety Symposium Manufacturers Award. Volvo has approached this thorny issue with a three-pronged attack. In order to prevent the XC90 going dirty side up in the first instance, sophisticated gyroscopically-controlled stability software steadies even the most radical lane changing behaviour. Should you hit a kerb or ditch and roll the XC90, it features a boron-reinforced roof to prevent the upper body deforming. Finally, the XC90 also features curtain airbags that stay inflated ten times longer than normal bags in order to ensure passengers are kept away from flying glass and insulated from doorframes during a roll.

Not a whole lot needed doing to keep XC90 sales strong but Volvo has pre-empted any buyer fatigue with a strong but well-judged package of improvements. Success is virtually guaranteed once again.

TOP 5 XC90 DEALS

The results below show the top XC90 deals on buyacar

	Volvo XC90 2.4 D5 SE Lux 5dr Off Road
	ETR	Mthly £555	Saving £4,049	Price £33,391
	Volvo XC90 2.4 D5 SE Lux 5dr Geartronic Off Road
	ETR	Mthly £580	Saving £4,204	Price £34,636
	Volvo XC90 2.4 D5 SE 5dr Geartronic Off Road
	ETR	Mthly £548	Saving £3,971	Price £32,769
	Volvo XC90 2.4 D5 SE 5dr Off Road
	ETR	Mthly £522	Saving £3,815	Price £31,525
	Volvo XC90 2.4 D5 S 5dr Off Road
	ETR	Mthly £482	Saving £3,537	Price £29,303

typical 9.72% APR

PCP finance quote over 48 months,  10,000 miles pa,  deposit of £1000