Jaguar uses aluminum to great advantage in the 2012 XJ. Mechanically it's not quite as advanced as some of its competition, but its relatively light, stiff body keeps curb weight down, which does dramatic things for acceleration and handling.
The XJ's aluminum body is glued and riveted together in pieces, the way airplanes are made. In all, an XJ weighs about 4,300 pounds, while other competitors can weigh hundreds of pounds more. But the body isn't the only place where aluminum makes itself known--it's also a big part of the XJ's drivetrain.
The XJ's aluminum-alloy engines are all derived from a single 5.0-liter V-8 configuration, one shared with the XF sedan and XK coupe. The standard version offered in the XJ and XJL sedan puts out 385 horsepower, and it's teamed to a six-speed automatic. With supercharging, the same engine makes either 470 hp or 510 hp, depending on the buyer's wallet size. We've been amazed how American this engine can sound: its vintage V-8 noises aren't at all quiet or syrupy-smooth, and the classic eight-cylinder rumble injects a note of seriousness into any stoplight challenge. The 385-hp drivetrain can toss off 0-60 mph runs in 5.4 seconds; the supercharged 470-hp engine is capable of a 4.9-second run; the Supersport, Jaguar says, will hit 60 mph in 4.7 seconds. The XJ is limited to a top speed of 155 mph unless you specify one of the new Speed or Sport and Speed packs, which lift the electronic limiter to 174 mph.
In most every way, the 2012 XJ is a brisk, engaging performer, and its relative lack of electronic add-ons keeps ride and handling more pure than in some of the perpetually-adjustable competition. The XJ goes about its work more directly, with an independent suspension with coils up front and links in back, electronically adjustable air springs in back, and an electronically controlled rear differential on supercharged cars. "JaguarDrive Control," activated by a console-mounted switch, lets owners choose Normal, Dynamic and Winter settings for the throttle, steering, transmission and ride quality.
The XJ may have a narrower range of user-selectable performance modes than German or Japanese luxury sedans, but we think it's better for it. Its reflexes are more pure, more predictable, and the overall driving feel is more unified. The driving modes are related more closely than, say, the settings programmed into Audi's chuck-it-now Drive Select system.
Big ventilated disc brakes with anti-lock, brake drying and good pedal feel match the XJ's crisp new feel. And Z-rated tires on 19- or 20-inch wheels stick admirably--though you'll certainly notice the long, storied reputation of Jaguar ride has also been ditched for a taut, athletic feel. The air mattress is gone; long live the Tempur-Pedic precision.