Custom tends to dictate that each successive model on a given theme is bigger and heavier than the one that precedes it. Not this one. This XK may be a mere 1.5cm longer than the old XK8, but thanks to that advanced aluminium construction, its weight has plummeted to 1595kg for the entry-level model. That's a huge 90 kilos lighter than the XK8, a car which weighed about as much as a Maserati Coupe and it's still less than BMW's 630i, a car that boasts the lightest six-cylinder engine in production. The XK's svelte lines aren't just an automotive trompe l'oeil. This design possesses an athleticism the old car can't match.
Look at the stance. Whereas the XK8 was undeniably elegant, it couldn't really claim to be especially dynamic in appearance. The long front and rear overhangs compromised cabin space and dated the styling a little, but the XK keeps the same basic premise, while toning up the whole look significantly. Designer Ian Callum had a tough task on his hands. He couldn't afford to alienate existing Jaguar customers with a gratuitously radical design, but by the same token, he strove to avoid becoming hidebound by Jaguar's heritage.
There are classic cues in the XK's styling if you know where to look for them. That oval front grille and the way the rear cabin tapers in over the haunches is classic E-Type. Even the front badge is a nod to this illustrious sports coupe. What Callum achieved is a tautness to the bodywork that's new to Jaguar. The car looks sinewy and muscular, the sheet metal stretched over something seriously purposeful. Spot the latest models by the telescopic aerial which is now concealed within the boot spoiler.
There's also a welcome injection of practicality to the XK. Whereas the XK8 was astonishing in having such a huge 'footprint' but such a tiny passenger compartment, the XK is a more spacious car altogether. The high hipline remains, but Jaguar has worked at making the interior feel a good deal airier, with a low scuttle and clever use of colour combinations. The wheelbase increased by 162mm and rear occupants will notice the difference immediately. Up front, there's way more room around the pedal box and beneath the steering wheel. Gone is the rather mean boot of the XK8 - unforgivable in a car with Grand Touring pretensions - and in its place is a more versatile hatchback arrangement.
The interior is rather restrained in the best Jaguar traditions. The old 'Spitfire wing' plank of wood that ran across the dashboard has been ditched, with a driver focused binnacle, a broad centre console and a rethink in the use of materials. The latest models feature revised door switch packs, column stalks and a choice of wood of aluminium trim inserts.
The Jaguar Smart Key system utilises a push button keyless entry/starting system. High technology features offered on the XK include adaptive bi-xenon lights, switchable TRAC stability control and traction control, Protec dynamic headrests, adaptive cruise control and the option of a tyre pressure monitoring system and run-flat tyres. The brakes have been upgraded with larger, ventilated discs with four-channel ABS. Unlike most digital ABS systems, Jaguar use analogue valves in the hydraulic control unit that subtly vary the brake pressure at each wheel allowing drivers to benefit from better steering response during particularly heavy braking.
Unlike earlier generations of Browns Lane cars which had their fair share of niggling faults, the XK has suffered no major problems, which is great news for used buyers.
The usual cautions still apply though: stick to main dealers or reputable specialists and don't be tempted by a potential bargain car that doesn't have its service history present and correct, especially the supercharged XKR which can suffer cooling problems if subjected to hard track use.
(approx - based on a 2006 XK coupe) A full exhaust system (without catalyst) is around £595. Front shock absorbers are about £110 a pair. An alternator is about £300 and a starter motor around £300. Front brake pads are about £100.
Jaguar designed the XK with a convertible model in mind, knowing that this is where the lion's share of sales would come from. There are rumours of a diesel-engined variant, but much more important is the availability of a 420bhp supercharged XKR model. The standard car gets a 300bhp 4.2-litre V8 similar to that in the XJ saloon. Due to the XK's weight loss plan, this car will jet to 60mph in 5.9 seconds and complete the standing quarter mile in 14.4 seconds - fully half a second quicker than the old car. In fact, those statistics are nudging towards those of the old supercharged XKR, which leads one to surmise (correctly) that a supercharged XK would breach 60mph in less than five seconds. The top speed of the XK is electronically limited to 155mph although should you possess a lighter right boot you should realise a meaningful six per cent saving in carbon dioxide emissions over the old car.
Opt for the XKR and things get even more serious. It's still got a supercharged eight-cylinder powerplant as before, but this time it's good for 420 rather than 370bhp. The Coupe model loses 70kg of weight and the Convertible sheds 100kg compared to its progenitor, so it's not hard to imagine the concussive punch the XKR can wield. Jaguar quotes a sprint to 60mph in just 4.7 seconds with the 50-70mph increment dispatched in a vanishing 2.5 seconds. An electronic limiter intervenes softly at 155mph, fast enough for most of us. Without the limiter, Jaguar insiders reckon that over three miles a minute are possible given the car's slippery aerodynamics and leggy gearing.
It would be tempting to think of this car as an evolution of the old XKR. Tempting but wrong. This XKR is built from entirely different stuff. The advanced aluminium construction and massively superior technology embodied in the latest XKR raise its game enormously. Let's take a closer look at the engine. With fully 120bhp more than the normally aspirated XK and good for a fulsome 560Nm of torque, the XKR has the firepower to make good on its aggressive styling. This is no crude old V8 with a blower bolted on. Designed to comply with the strictest emission laws, this unit features four valves per cylinder, variable valve timing and an electronic return-less fuel system.
A Variable Inlet Camshaft Timing system helps boost torque at low revs while the engine's breathing is helped by twin air inlets. Drivers will notice that the 'four milk floats of the apocalypse' sound of the old XKR's supercharger under full acceleration has been muted to allow more of the engine note to dominate. This is a good thing as at higher revs, the 4.2-litre unit has an almost Aston-like aural signature. A paddle-operated six-speed Jaguar Sequential Shift automatic transmission handles the gear changing duties.
Jaguar has had a rather inconsistent run of form in recent years. There are cars that look better than they are, cars that are better than they look and then there's the XK; a car that looks great and drives brilliantly. Used examples represent an excellent way to get what remains one of the most desirable GT cars around. Our choice would be an early XK coupe.