Jaguar has at last achieved the seemingly impossible. It has managed to reverse the established laws of diminishing performance, finally proving that big saloons forced to borrow powertrains from their smaller, lighter brethren need not be hampered by inferior performance. I stand to be corrected, but I am not aware of any other large saloon car whose claimed acceleration times and top speed are better than those of the model below it in a manufacturer’s line-up. Both can be said of the new diesel XJ, which borrows its engine from the S-type.
I’ve driven the XJ6 D at a pivotal point in my relationship with the diesel motor car. I have now had my fill of very high-performance oil-burners and have tried enough to know that none, bar perhaps the VW Touareg V10, is as accomplished as a petrol equivalent in the areas that matter to thee and me. They have plenty of torque, but torque is like a good single malt: medicinal and helpful in the correct dose, disruptive when over-indulged. The motor industry is growing ruddy-faced on the stuff and will soon collapse from inebriation.
So rather than sniff at Jaguar launching the XJ6 D two weeks after Audi announced that the A8 will have a diesel lump capable of pushing the Queen Mary, I was pleased at the honesty of it all. It may not be the fastest, was the message, but it might just be the best.
Were it not already considered the sweetest engine in the class, there might be raised eyebrows surrounding the news that this engine is almost identical to that in the S-type 2.7 D. The engine has been moderately remapped for further refinement, but S-type owners still trying to work out if their engine is running or not will attest to the fact that this motor was already smoother than a Waxoyled Des O’Connor.
So the numbers are the same: 204bhp at 4000rpm and 321lb ft at 1900rpm. Both fall short of the equivalent Mercedes and BMW models, but then they don’t have the benefit of a 1659kg kerbweight. Isn’t it curious how Land Rover is being pilloried for making grossly over-weight tractors, while its saloon-car building cousin quietly produces a remarkably light executive barge? A fully laden BMW 730d is 1975kg, which equates to a power-to-weight ratio of 115.4bhp per tonne compared to the Brit’s 122bhp per tonne, although the Seven does claw the difference back in torque to weight.
Claimed performance data (7.8sec to 60mph and 141mph top speed) simply isn’t needed when deciding whether this car has enough performance. There is ample shove for the intended role and what pleases me most is that this is the first new XJ to go about its business the way you expect a Jag to. It’s not a sprinter, it’s a loper, a car that arrives at a cruising speed without ever informing the occupants how it managed to do so.
Large executive saloons need two aspects of their engine’s performance repertoire to be top-notch; if they can achieve these, then what happens in other areas is of little importance. First and foremost is step-off acceleration: the athleticism with which the car leaps from a stationary position. The other is cruising refinement at the vehicle’s natural multi-lane waft. Too many cars in this class require an unbecoming hoof to get them moving, and then the engine only settles to a distant mew at speeds that would raise eyebrows even on an autobahn.
This diesel satisfies both of these criteria so well that its position as the pick of the XJ range is already assured before we even consider the economy benefits. It swooshes away from a standstill with the slightest flurry of diesel combustion rattle, and the fleshiest part of the torque parabola has been so well coordinated with the first gear ratio that from rest to 25mph it might be faster than the supercharged XJR.
Above 40mph you barely hear the engine, and if a few noises have eluded the engineers, then they’re very incidental ones. And sure enough, at anything between 80mph and 110mph - surely the speed range within which most XJDs will find themselves living - the motor is mute. New laminated glass reduces the original XJ’s biggest weakness - acute A-pillar ruffle - to an acceptable level. On smooth surfaces the 19in Pirellis are far quieter than you’d expect, and suspension noise is well hidden, too. Tellingly, to have a conversation with someone sitting in the back seats of this car, you barely have to raise your voice.
Our test car was a Sport Premium version with a provisional £49,895 list price, and it comes loaded with gear, but given the prominence of the S word in the name, there’s one obvious omission from the list of standard kit. It doesn’t have Sports suspension, nor will it be an option. And Jaguar should be applauded for making such a decision - it will protect countless customers from making inadvisable spec choices.
What this means is that just as the powertrain smooches you about in an entirely Jaguar manner, the air suspension is free to cosset and smother all nastiness contained in the road surface. And that has to be the supreme test of a genuine Jag - the ability to levitate over the road surface and retain enough composure to continue working at high speed. So while the rear end is happy to use most of the suspension travel over faster undulations, the car never feels over-stretched. Some will find these comments curious, but to me they’re a crucial step in the evolution of Jaguar as a brand. Remember, it has a reputation built as much on supremely refined and comfortable saloons as it has on sports cars. Both Audi and BMW build executive cars whose ride quality, when fitted with large wheels, is the weakest part of the package. This is where Jaguar can establish genuine class leadership.
To sit in the XJ isn’t the fiddle and grin experience you have in an Audi A8, but then again it isn’t as confusing as a 7-series. It’s a simple, unadventurous cabin with a prominent centre console and just about enough wood and retro-architecture to pull off the trad Brit feel. The ergonomics are excellent, as is the sat-nav/hi-fi touch-screen, and the Sport model is fitted with XJR seats which should be standard across the range, such is the improvement over the regular items.
Even though it will never be driven with such a lack of deportment, we ought to touch on the finer aspects of the handling when hustled. Being so light, the XJ certainly feels more agile than anything else in the class and can be threaded with accuracy. Pile into a bend with too much enthusiasm and it will understeer as expected. Equally, wet roundabouts and disengaged DSP will elicit a similar response from the rear. Otherwise it’s neutral and the steering has some feel, which is remarkable in a modern luxury saloon.
The fuel economy issue is rather confusing. Not being in a position to refill the car and use our own figures I had to rely on the trip computer, which is normally very accurate in Jags. Problem was that after 65 moderately speedy miles the old smoothy was only registering 26.4mpg. But a colleague driving in precisely the same manner over identical roads returned 32mpg. For once I’m inclined to give the XJ the benefit of the doubt, but that trip computer is spreading unhelpful and potentially damaging propaganda. People on test drives won’t be impressed. With a claimed 35mpg on the combined cycle, compared to the BMW’s 34.5mpg, and a 214 g/km CO2 output, the Jag is right up there for cleanliness.
Unless I was dealing with a committed xenophobe, I’ve always found it difficult to recommend an XJ over its German rivals because they all did the job of stress-free travel rather better than the Brit. But the XJD is one of those cars blessed with some outstanding attributes that still manages to offer the driver and passenger rather more than it should. For me it resurrects the notions of Jaguar-ness as I’d imagined they should be: a car of charm and consistent ability, a car you’ll step out of more relaxed than you would from the opposition but without being able to explain exactly why. Yes, it’s very refined and offers fine ride comfort. But crucially, it’s ever so slightly aloof. Germans makers have been trying, and failing, to build this quality into their cars for years, but Jaguar can still manage the trick spontaneously. Long may it continue.