JAGUAR has been experiencing some birth pains with the new XJ supersaloon.
But this complex four-door saloon is weaning well and is guaranteed to grow up quickly to occupy a pole position in the rarefied ranks of the "best cars in the world".
It cost a shedload of cash to develop, has one of the most advanced electronics systems fitted to any car in its class, has a featherlight alloy body that tips the scales at just 1.79 tonnes, and the imposing good looks of a modern Jaguar that’s guaranteed to get itself noticed.
Additionally, it is probably the most important Jaguar for a decade – a vital luxury banner waver for a famous marque.
When it went on sale on May 22 it was late on parade. Final fine tuning and honing to make this great car perfect delayed its debut, and even now Jaguar quality assurance electronics engineers are poring over every production example to ensure owners receive nothing but the best.
I was lucky enough to get my hands on the first XJ in the Highlands – Macrae & Dick’s 275bhp three-litre twin turbo V6 turbodiesel in impressive Portfolio trim.
This high specification model uses the same power plant that drives the smaller Jaguar steel-bodied XF in S trim that I tested some months ago in the dead of winter.
But with its colossal torque – no less than 442lb.ft streaming in from 2000rpm and, believe it or not, a body that is lighter by seven kilos – this new XJ feels more agile and belies its 5.12-metres length.
The Macrae & Dick car came with a trio of options – about all that anyone would want to add to an already impressively generous Portfolio standard.
In addition to its standard equipment, the car was fitted with a DAB radio that cost £250, a digital TV receiver priced at £500, and splash guards that added another £200.
That still only brought this magnificently equipped luxury express to £65,350. In this class that’s virtually bargain territory.
I’m never entirely happy with Ian Callum’s new Jaguar designs when I first see them – but inevitably I soften and moderate my opinion.
The XF had that effect on me – grumblingly doubtful at the launch and later accepting and finally approving.
The XJ falls into the same camp. The front and flanks are awe-inspiring – strong, purposeful but retaining a sleek taste of the design DNA that made Jaguar what it is today.
But my jury is still out “round the back”. The good news is that the tail end delivers incredible boot space – a massive 520 litres that will take the breath away from any XJ owner used to the earlier flat-decked designs.
There’s no shortage of space here for golf clubs, large cases or any bulky executive cargo you might want to transport.
But the statistics and practicality can’t hide the car’s considerable rump. It’s like the bum on the Porsche Panamera – generous and well-rounded.
But you can’t have it both ways. If you want a large car to carry a large cargo, it won’t compress as if by magic into a nicely proportioned sleek boot.
Capacity for practicality’s sake means bold treatment – and that’s precisely what Ian Callum has done.
It’s certainly not ugly, just rotund and fulsome – but I do wish its tail lighting lenses and contours didn’t remind me quite as much as they do of a Citroën C6!
But this is a car destined for great things. It drives as majestically as it looks.
Putting the power down is a revelation. Grip from the rear driving wheels is spectacular, thanks to advanced chassis and power management electronics.
But brute power is balanced by excellent steering, an outstanding suspension, and a generally refined and silent ride.
You get a lot from the XJ – mile-eating satisfaction being top of the list. But what will surprise many is its economy potential.
Driving sedately along the A96 from Inverness in the direction of Banff, I averaged an amazing 43mpg – nearly 3mpg above its official combined figure.
Even when I took to the hills and the single-trackers of the Dava Moor and slipped into "sport" mode and dropped the chassis into "dynamic", the consumption was no worse than 35mpg.
That’s remarkable for such a bulky car, and a great tribute to fine aerodynamics and the efficiency of the three-litre twin-turbo V6 diesel – the same unit that powers the new Discovery 4 and Range Rover Sport.
The six-speed automatic transmission with paddle-shift is smooth and responds instantly to paddle commands.
It adds a sporting dimension to a large car that can easily revert to smooth cruising character when left to its full automatic mode.
Design is part of the appeal of this excellent British-built luxury car – and the dash is worthy of special mention.
The dials look conventional enough – analogue with chrome bezels. But look closely and you’ll see they are computer generated representations – damn good ones at that.
In standard drive they remain white on black, but select "dynamic" mode for the chassis and "sport" transmission at the same time and they subtly change to red.
Cleverer still is how the speed and revs are highlighted as the needle sweeps round – a brightening of the appropriate digits Jaguar calls "Torchlight" that grabs the driver’s attention, then fades as the needle either continues to climb or fall back.
It’s a nice touch.
It’s this application of advanced electronics that singles Jaguar out. Like the XF, the transmission selector rises from the central console when you press the starter button to activate the ignition – it’s like something from War of the Worlds.
The main touchscreen controls myriad functions, from front and rear climate to the stunning sound generated by the Bowers and Wilkins audio equipment, the TV and radio function, navigation, rear view camera and much more.
Meanwhile, the main dash panel carries trip computer information.
Then there’s the deeply-dished steering wheel, electrically heated and richly trimmed in leather on the Portfolio.
From the superb driving position, the dash is a deep scallop sweeping ahead of the front occupants with a modest walnut trim, and each door has a huge high gloss walnut capping panel.
It looks great and, with the fine leather trim, is firmly in British tradition – but I fear that glossy panel is bound to be at risk of scratching from ladies with finger jewellery!
The headlining is worthy of mention – black suede. It has a high quality look and sets off the Portfolio’s twin glass roof panels and their wide-opening tilt and slide front section.
No matter which XJ takes your fancy – the stunning 3.0D I had on test, the 385bhp five-litre V8 petrol or its incredible 510bhp supercharged sister – the new Jaguar flagship is an impressive piece of luxury kit.
And if the already spacious standard wheelbase cramps your style, there’s a long wheelbase model that adds five inches into the rear seating space.
Prices for the 12-model family start at £53,900 for a V6 diesel in Luxury trim, rising to £91,000 for a long wheelbase five-litre Supersport.
The mid-range 3.0 Diesel Portfolio I had on test drives superbly in the best Jaguar traditions. It handles like a fast executive.
It’s as nimble as a car half its size and, with its rear drive layout, delivers a driving and comfort experience that will delight both its pilot and its passengers.
It’s a class act.
Rating: 9/10
FINAL THOUGHT: When it comes to cars in the super saloon class, there’s a lot of competition. Despite a packed field that’s just been rocked by the dramatic arrival of the superb new Audi A8, Britain’s latest Jaguar XJ is a giant among luxury cars with outstanding technology, incredible comfort, and a driving experience to rival the best.