Jaguar's XJ is a car most will be aware of, but few could claim to be really familiar with. Its comparative rarity works both for and against it. On the one hand comes the cachet of being more readily associated with ferrying the prime minister or members of the royal family to state banquets than UberLUX-ing a hen party to Nandos. On the other, reality: it just isn't quite as good as an S-Class across the board, and sales have reflected that.
The PH-iest version, however, was never going to be a huge seller, given it's the flagship performance variant of Jaguar's flagship luxury model - and therefore something of a contradiction in terms. Many if not most XJs are bought to be driven in, not to drive, and unless your chauffeur happens to moonlight as the Transporter, there really is no need for him to have so much welly under his right boot.
Nonetheless, just as it's impossible to resist another go in the car on UK soil, it's worth reiterating precisely what happens behind the wheel of Jaguar's £93,780 saloon, because, contradiction or not, the combination of supercharged V8 and huge, softly sprung saloon is tremendous. The power delivery is sumptuously smooth, and with the SVR-grade 575hp available to the rear wheels, it launches the 'Velocity Blue' car from a standstill to 62mph in just 4.4 seconds and on to a top speed of 186mph. That's 0.2 seconds less and 12mph more than were achievable in the previous, 550hp version.
The average XJ buyer is unlikely to be preoccupied by 0-62mph times, but it's hard to believe the R version attracts the archetypal customer. There's unabashed pleasure to be had from planting your right foot and stiffening your spine against the seatback as the 8-speed 'box seamlessly shifts its way through the gears, quad exhausts rumbling contentedly. And once it's underway, the 575 surges into its element, offering supreme performance between 40-90mph, along with the kind of hushed refinement that makes a liar of the speedometer.
On anything windier the big Jag is naturally more of a handful. The beautifully weighted electrically assisted steering does an admirable job of maintaining Jaguar's reputation for dynamic excellence, and it's by no means ungainly for a car of its, or any, size. But while 1,875kg is far from lardy for the segment, it's still a lot to shift down a B-road. It's rare that you forget you're in a 1.9m wide car, or one that it's over 5m from nose to tail,nor is it unusual to begrudgingly admit that the vaunted seat of an SUV would make it easier to pilot.
Inside, the cabin benefits from a plethora of driver aids made possible by the scrapping of the hydraulic steering, including semi-automatic parking and lane-keeping assistance, while the infotainment system now boasts a 10-inch touchscreen display. The tech still ranks among the least intuitive and most frustrating to use in the industry, though, and Jaguar has not succeeded in making every inch of its trim feel on par with its German rivals. Added to which, in sunny conditions, thanks to the rake of the vast windscreen, the glare from the chrome trim and polished plastics of the centre console can be a genuinely enraging peripheral presence.
The real shortfall though is in the 575's inability to completely paper over the acknowledged cracks in the XJ's appeal: the most notable among them being the model's age compared to its closest rivals. The S-Class is far more comfortable in the back, a Panamera is better in the front and an 7 Series is more agreeable to look at. And that's before you even get to the seemingly unstoppable migration of buyers from big saloons to big SUVs, where the combination of power, space and prestige is readily available (not least from the senior partner at JLR).
But - and there is a but - no sense-talking ultimately threatens to drain the appeal from the 575. The XJR practically oozes satisfaction, even when there's quantifiably more of the stuff on offer elsewhere. It should also be added (lest we forget) that the days of the V8-powered saloon are unequivocally numbered, and in the years to come we'll likely be yearning for a time when you could buy a big car with an engine as superlative as Jaguar's supercharged 5.0-litre V8. This iteration of XJ isn't long for this world and its replacement will almost certainly benefit from electrification, which absolutely makes sense for tomorrow. The XJR 575 absolutely doesn't, and it's all the better for it today.
SPECIFICATION - JAGUAR XJR575
Engine: 5,000cc V8, supercharged
Transmission: 8-speed automatic,rear-wheel drive
Power (hp): 575@6,250-6,500rpm
Torque (lb ft): 517@3,500-4,500rpm
Top speed: 186mph