If there were any doubts about a petrol-driven firm like Jaguar partaking in a little oil-burning exercise, these must surely have been dismissed in the last four months of 2003.
During that time, Jaguar's first foray into the diesel market, resulted in a third of all X-Type sales being powered by diesel: this despite the fact that the engine in question was nothing more than a reworked Ford Mondeo block.
While that can be regarded as something of a stop-gap effort to prevent it losing massive market share at a time when diesel sales were rocketing, we now have the fruit of Jaguar's diesel labours, a brand-new engine built in partnership with PSA Peugeot Citroën, an old hand at creating good quality oil-burners.
Jaguar badly needed this new engine and it's been worth the wait if it opens the S-Type up to the massive growth in executive diesels.
According to Jaguar figures, diesel now accounts for one in three sales across the premium segment in Europe and by the end of next year, this is expected to have risen to 40 per cent.
The introduction of the new diesel unit comes with some minor styling and specification changes to the S-Type. These concentrate on new rear-end design and a new aluminium bonnet, dynamic improvements, enhanced interior features and a wider choice of equipment.
But the big news is under the bonnet. The four-cam, 24-valve, twin-turbo V6 features the second-generation common-rail direct injection, offering 206 bhp and 435Nm of torque; that's more than the naturally aspirated 4.2-litre V8 petrol engine.
Combined fuel economy is claimed at 40 mpg, while in the extra-urban cycle this rises to 49.7mpg. It has a top speed of 140 mph and manages 0-62 mph in 8.1 seconds in six-speed manual format, or 8.2 seconds in six-speed automatic.
Of course, most S-Type owners will opt for the automatic gearbox, and rightly so, for the manual box does the car a disservice and is best avoided. The gates are imprecise, the gearstick badly positioned and the overall effect is rather like stirring porridge.
While the suspension was revised in 2002, with the heavier engine to the front the car still suffers from body roll, though most S-Type drivers prefer the soft smooth ride of the executive motor and would accept some roll rather than a stiffer sporty setting on Irish roads, which over the long term can lead to discomfort and annoyance.
The look has not changed dramatically, the reason given that buyers are essentially happy with the current styling, so why change it? The major difference is in the car's stance. The revised S-Type takes a more aggressive stance, with a higher rear and the nose pointing slightly down.
Inside, Jaguar is at last taking the sporting characteristics to heart, with an optional aluminium finish instead of the traditional wood. The wood has too many old boy's club connotations for some younger audiences who regard themselves as still too youthful for a cravat and monocole.
Prices have yet to be fixed but expect them to be in the region of €64,000, coming in between the 2.5-litre and 3-litre petrol versions.
Of course the S-Type's main competitors will not be from the petrol stable. Rather they will come from the likes of the BMW 530d and the Mercedes S270 CDi.
Of these the BMW is probably the best all-round package and both German competitors beat the S-Type in terms of the 0-62 mph dash. But their Achilles heels are probably in pricing, where optional extras - such as floor mats - can push the price of the BMW 530d significantly above its listed €65,510. That's where the S-Type may make its mark.
Of course most S-Type sales will be in Luxury format, as anyone seeking a Jaguar must surely go for leather interior and trim, if only to preserve their resale value.
Sadly for Jaguar salespeople, the diesel will not be here until June, though the facelifted petrol version should be in dealerships within the next week or so.
SUPERCAR IN A SUPERCAR ZONE
Alongside the minor tweaks to the S-Type, Jaguar has retouched its XK range. Though hard to spot, there have been very minor changes to the nose and rear section of the XKs, while the XKR gets a new mesh grille and a lower front bumper.
With new superb looking 20-inch shining silver alloys, the XK attracts plenty of attention. On a sunny day in the south of France we couldn't resist spending time at the wheel of the revised XK-R convertible.
With its supercharged 4.2-litre engine droning out a deep-pitched gurgle and whirr at every touch of the accelerator, it fitted in well with the accompanying supercar traffic.
Yet for all the high revs and classic looks (courtesy of a sea-blue exterior and champagne-white leather interior trim), the layout and equipment of our top of the range XKR convertible lacked the expected panache of a car costing 132,695. There's a mass of buttons on the dash, far away from the impressive touchscreen system in the S-Type and XJ range. With roof down, the rear cover also caught the wind. Some things about the updated model look increasingly dated. But the supercharged engine remains a joy.