But a raft of extra benefits promising substantially lower ownership costs are expected to allow the new XJ models to dominate the upper reaches of the diesel corporate sector for some time following their introduction later this year.
Two years after arch-rival Mercedes-Benz took the diesel lead, Jaguar is launching a twin-turbo V6-powered model this autumn. Bristling with advanced features, the 2.7-litre cars set a fresh benchmark in diesel refinement with whispering high performance. But they also boast lower insurance costs, reduced servicing and maintenance – and class-leading benefit-in-kind tax liability.
Jaguar UK managing director Phil Popham said: ‘We think our new XJ places us in our best position for years to make the most of the dramatic swing to diesel – and that’s remarkable, considering less than two years have passed since we fired up our first diesel engine.’
Speaking as the diesel model made its debut, Popham said: ‘Our lack of diesel meant we lost out to Mercedes-Benz, but I’m looking forward to regaining our pole position.
‘Petrol will continue to power our entry-level XJ, but the signs are that diesel will soon be taking over as our core offering and driving at least 65% of our top models.’
Due on the road in September, the diesel cars are expected to boost Jaguar’s present 25% share of the luxury segment by 10%. But Popham insists the main job of the new models will be to consolidate the firm’s position, rather than grow it.
He added: ‘With a total of only 9,200 sales in the segment last year, this is a very competitive area. Providing exactly what the corporate customer wants is critical to success, of course, so I’m very grateful for the effort put in by our engineers. They have made tremendous advances.’
Refinement and minimal noise levels will be central to the success of the models, which share the same engine introduced last year in the smaller S-type.
After more than a decade of trials with diesel, the decision to finally go ahead with a move viewed as unthinkable by Jaguar aficionados inspired the engineering team to strive for class-leading packaging.
They also set out to hone diesel characteristics to match petrol as closely as possible, and one result of this work is a unique engine mounting system which harnesses electronic control to counter vibration, one of the banes of diesel power. The gadgetry – an industry first – cancels out vibration on idle by 90%.
The team came up with another novelty – a bonnet liner with integrated side seals – to further cut back the level of noise reaching the interior, and Jaguar has become the first premium car producer to introduce acoustic laminated glass, a move which trims both wind and engine noise by as much as five decibels compared with standard glass.
As well as concentrating on refinement, Jaguar has also made sure the diesel XJs make financial sense to fleets.
A £2,000 premium takes the on-road price of the XJ TDVi Executive to £43,995, but its CO2 emissions figure of 249g/km means it costs a 40% taxpayer £64 a month less in company car tax than the 3.0-litre petrol version.
Elsewhere, the monthly tax savings range from £50 compared with the BMW 730d to £140 over the Mercedes-Benz S280.
With an increased standard mileage service interval over petrol models, Jaguar claims routine maintenance for XJ diesels will cost 7% less over five years, and Jaguar is claiming a 27% saving against the Mercedes-Benz S320 CDI, which costs £51,840.
Popham said: ‘Our car costs substantially less than its rivals, so we’re in a position to offer better value as well as reduced ownership costs. We’re not asking our customers to trade performance for refinement nor economy for power. This is a true Jaguar, just like every other XJ.’
Behind the wheel
THE way an engine is installed has always been paramount to the perceived refinement of diesel power, but Jaguar’s clever new cocktail of advanced engineering puts the XJ in a class of its own.
That’s only the start of the biggest single advance in diesel motoring this decade, however. Despite being bigger than the S-type, which also uses the V6 motor, the XJ actually weighs a lot less because its bodywork is built in aluminium instead of steel – and that means it uses less fuel than the smaller car and has the potential to return an amazing 43.7mpg at steady cruising speeds.
The light weight also promotes more zippy acceleration than you’d expect – 60mph comes up in just 7.8 seconds – and sharp, precise handling makes the XJ a delight. As with petrol versions, ride comfort is superb and the self-levelling air suspension lowers the car at speed for greater stability.
AS impressive as the XJ TDVi is on the open road, the car makes its biggest impression when the ignition key is turned for the first time: the engine sounds like it is running on unleaded. The bonus is that the engine also has the feel of a petrol unit as it works through its six-speed auto transmission with silky smoothness.
For high mileage users, this is a dream car so well worth its relatively modest price premium that for many buyers there seems little point in opting for the 3.0-litre petrol V6 version. Or, perhaps, a BMW, Mercedes-Benz or Audi for that matter.
Engine (cc): 2,722
Max power (bhp/rpm): 204/4,000
Max torque (lb-ft/rpm): 321/1,900
Top speed (mph): 141
0-62mph (sec): 7.8
Fuel consumption (mpg): 35.0
CO2 emissions (g/km): 214
On sale: September
Prices (OTR): £43,995-£49,995