Unlike Lotus and Aston Martin, other stalwart bearers that make the most of aluminum tubs, the XK has, as noted, a full aluminum unibody. It's derived from the XJ's, with different, and more numerous, aluminum extrusions and castings topped by pressed aluminum panels. The entire structure is bonded and riveted, with the exception of one weld in the roof seam of the coupe. Even in convertible form, the impressively rigid XK needs no additional gusseting. Jaguar further avers that its aluminum structure provides greater safety as well as a service life double that of steel. The only problem is that it is hugely expensive to manufacture. We say it's worth it.
Jaguar claims best-in-class torsional rigidity for its new coupe and a 32 percent improvement over the outgoing model, while the convertible is half again more rigid than the decidedly wobbly structure it replaces. Yet bucking the trend toward ever-heavier cars, both XKs are lighter than the models they replace, with the coupe tipping the scales at a robust but not disgusting 3671 pounds and the convertible at 3759 pounds (versus 3779 and 3980 pounds for the outgoing cars).
Deploying the latest, 300-hp version of Jaguar's proven 4.2-liter AJ-V8 (up a mere 6 hp from its predecessor, courtesy of modified fuel injectors), the svelter XKs post power-to-weight ratio improvements of five (coupe) and eight (convertible) percent, enabling the coupe to reach 60 mph from rest in 5.9 seconds while turning the quarter-mile in 14.4 seconds (factory figures). That's but half a second slower than the outgoing XKR with all 390 of its supercharged locomotion units. Look for a new XKR-and the best-accelerating production Jaguar ever-in approximately a year's time.
Throttle-by-wire technology helps cut emissions to meet ULEV-II standards but, as always, blunts excitement, with throttle response that is smooth but not crisp. Underscoring the remarkable silence achieved inside the car, induction roar has been muzzled out so completely that it has been judged necessary to actually pump some of the sucking noises back into the cabin via a rubber sound hose in order to enhance aural pleasure. It's a start, but the XK's exhaust note (which sounds bitching from outside the car) is experienced as a somewhat subdued version of the classic V-8 woofle inside the cockpit. We could deal with something a little rootier, tootier, and fruitier, but maybe that's just us.
In recognition of the outgoing XK8's lack of credibility in several key areas of tactile luxury interface, the company worked hard to keep the bean counters at bay in the cabin, the result being a new standard for modern Jaguar interiors. Although for this old-timer's money you'll never beat the wood, leather, black metal, and chrome simplicity of the old ones, a completely new design language for the XK and a new set of suppliers have resulted in an understatedly handsome yet truly luxurious office for a driver and one well-cared-for passenger. As in the past, those who find themselves relegated to either of the two incredibly tiny back seats are advised before attempting to sit down to be either dead or heavily sedated. Or they'll soon be wishing they were.
In the regal chairs up front, drivers benefit from more than just the higher-quality materials, although the stitched, leather-covered dash and door panels are among the first upgrades one notices. Wood veneers, in one's choice of burl walnut or light poplar, instantly, cosmically surpass the overly shiny plasticized stuff that graced the XK8. Add top-quality woolen carpets, and the new XK bespeaks English civilization of a higher order, giving BMW and Mercedes-Benz a run for their money for the first time in decades yet still managing to move the clock forward. It is decidedly not fake retro. One can choose aluminum accents in place of wood, and these harmonize just as convincingly.
The hugely adjustable seats are as comfortable as they look. Backaches were never the better part of valor, but they were a part of the outgoing XK. The new seats work with the rest of the car to deliver what must be one of the most relaxing sports-car experiences known to man. Improved head, leg, and shoulder room heighten the sense of luxury, while the decision to move the electric seats' control panels to the door-Mercedes-Benz style-addresses our other major gripe with the old car's seating provisions.