THERE is a commonly-held belief among many people that Jaguar is a bit set in its ways, old-fashioned and somewhat scared of change.

Owners are perceived by some as pipe-smoking, cardigan-wearing retired RAF squadron leaders.

However, the big cat seems intent on shaking off these stereotypes and the ever-changing face of the S-Type saloon is a guiding light in the struggle. Three revisions in five years to the styling and mechanics of the S hardly smacks of a firm clinging to the past.

The introduction of a 2.7-litre V6 diesel unit to the range also shows a willingness to embrace the current pan-European shift towards diesel power. If Jaguar's figures are correct and 80 per cent of all D/E segment cars sold in Italy and France are oil burners, then they would have been foolish not to follow suit.

Jaguar's new twin turbo V6 diesel may be based on a PSA (the partnership between Peugeot and Citroen) block, but all of the finishing touches and performance jiggery pokery were carried out at the firm's Whitley base. This becomes evident with the facts and figures - 206bhp, 320lb/ft of torque as low down as 1,900rpm, nought to 60 in 8.2 seconds and a top speed of 141mph.

Its twin low-inertia turbochargers have been tweaked to offer an improved transient response (reduced turbo lag) and Variable Nozzle Technology (VNT) helps to optimise the energy extracted from exhaust gases.

So, this is a high performance ripsnorter, then? Well, not exactly. While the Jag develops more torque than its 4.2-litre V8 petrol sibling, the smooth, unhurried manner with which it transfers the power to the wheels makes for very civilised horizon-chasing.

At motorway speeds in sixth gear, the S-Type is one of the most relaxing cars I've ever driven. While the now standard 17-inch wheels throw up a bit of road noise, 70mph evokes little more than a distant hum from the engine and trips of several hundred miles are dealt with effortlessly.

In fact, according to Jaguar, the S is seven decibels quieter while accelerating in second gear than a "nameless German rival".

On swooping and bendy roads all but the most timid drivers will be tempted to slide the gear stick across to the semi-automatic gate and make full use of the S's revised suspension. Uprated dampers and springs afford the Jag a sporty yet civilised stance with body roll only experienced during the most loutish of moments.

There have also been a number of stylistic changes made to the interior and exterior of the mid-sized Jag. The trademark front grille has been squared-off giving it added prominence and both bumpers have been smoothed and simplified. The rear light clusters have been elevated, raising the boot line and affording the S a more muscular appearance.

While these subtle changes to the Jaguar's styling give it a more contemporary feel, they also raise a few practicality issues. For example, the elevated rump may improve the car's looks, but it also raises the rear seats, making it a lot harder to see out when reversing.

Boot space too is a slight concern, as the opening is fairly narrow. This makes loading larger objects unnecessarily difficult.

Interior alterations continue the shift towards modernity. The new aluminium effect instrument cluster has a clean, minimalist feel to it. It is also rather refreshing these days to come across a new car without the seemingly mandatory overlapping dials.

Wood is still very much the order of the day across much of the range, with a variety of vibrant shades available in the 04 S-Type. In Sport and R models, however, tradition and heritage are put to the sword completely because, for the first time in the firm's history, an aluminium-detailed fascia is being offered instead of wood.

With the S, Jaguar has taken a savage swipe at those who would label its products quaint and old-fashioned. A more modern approach to styling and engineering will almost certainly bring people's perceptions of the big cat kicking and screaming into the 21st century.

This is an extremely important car for the Coventry-based firm. The executive saloon market continues to go from strength to strength and the Ford-owned prestige marque needs to consolidate its market share. Taking the BMW 525d and Mercedes E270CD head-on will require a high-quality product with very few chinks in its armour. But does the S match this description?

The revised looks are a marked improvement, if still a little retro for some tastes, and there is very little, if anything, wrong with the performance of the diesel engine.

In terms of build quality and luxury feel, it may even be possible that Jaguar has managed to out-German the Germans.

But it remains to be seen whether this will be enough to lure image-conscious executive types away from their Teutonic cruisers and their ultra cool badges.

For more information, call Webbers Jaguar on 01256 300646.