Driving Impressions

The Jaguar XJ benefits from an all-aluminum monocoque. Although the new body, introduced in 2004, is larger than the previous generation's, it weighs 400 pounds less. That's equivalent to removing the weight of more than two passengers. Even the long-wheelbase version adds back only 53 pounds. Those who might be concerned that an aluminum body is not as strong as a steel body can rest assured that this body is just fine. Like the shell of an airplane, the Jaguar's body is riveted (with about 3200 rivets) and bonded (with 120 yards of adhesive) to form an immensely stiff body shell that meets or exceeds all safety standards. Perhaps more important, the body is 60-percent stiffer than the one it replaces. This rigidity and absence of weight lead to a better handling car.

Toss this big car into a tight corner on a narrow winding road and you'll find it tenaciously hugs the road surface with nary a complaint. It's just what one would expect from British engineers who learned at an early age how to drive fast along those narrow country lanes. It's no wonder the world's fastest racecars are built in England.

The power steering is precise without being too heavy and the new XJ goes where it's aimed. The tires stay glued to the road thanks to the double-wishbone suspension design and Jaguar's Computer Active Technology Suspension (CATS) that continuously and instantly adjusts damping. CATS ensures stability whether the car is undergoing heavy acceleration, hard braking, or traversing an undulating road. During several hundred miles of driving on a variety of different roads and surfaces we found the car was stable and handled predictably at all times, and it didn't matter whether we were in the standard or long-wheelbase versions. The only intrusive element to the smooth ride was a bit more vibration through the steering column than is expected in a super luxury car.

These cars are quick. The XJ8 with its 300-horsepower V8 engine can accelerate from 0 to 60 mph in about 6.3 seconds, according to Jaguar. The V8 engine delivers good low-end torque so power is instantly available. And it offers good fuel economy for the class, with an EPA-rated 18/28 mpg City/Highway.

Shifting is seamless thanks to the six-speed automatic transmission. Jaguar's J-gate transmission allows you to flick the lever to the left and manually shift gears, if you wish. In reality, there's enough power and the electronic brain controlling the gearbox does such a good job that shifting manually seems superfluous.

Super V8 and XJR models boast a supercharger that forces air into the engine, producing 400 horsepower. This propels the XJR from 0 to 60 mph in 5 seconds, according to Jaguar, very quick indeed. These rocket ships also get a stiffer suspension, bigger brakes and fat 19-inch tires that grip the road and sharpen the steering response. Amazingly, the ride is not too harsh despite the short sidewalls. But it is the whine of the supercharger as you press the gas pedal that sets the XJR and Super V8 apart from the rest of the pack. The supercharged XJs face no gas guzzler penalty.

Brakes on the XJ models, which were already powerful and smooth, are improved on 2006 models with larger front and rear rotors. Supercharged models get a new Conti-Teves R Performance system with ventilated front rotors for 2006. The XJ has an electronic parking brake; a lever switch is pulled to set it and it's automatically deactivated when drive or reverse is engaged, an elegant setup.

Summary

The Jaguar XJ models are comparable to the best luxury cars in the world. The XJ is a beautiful car that swaths its occupants in traditional British luxury with rich wood and leather while sparing us of gadgetry. Its rigid chassis and sophisticated suspension offer a smooth ride and impressively good grip. The long-wheelbase versions offer more interior without trade-offs, and the Portfolio edition raises Jaguar's profile among the ultra-luxury cars.

NewCarTestDrive.com correspondent Larry Edsall reported from Phoenix, with Greg Brown in Las Vegas, Mitch McCullough in Los Angeles, and John Rettie in Santa Barbara, California.

Model Line Overview

Model lineup:Jaguar XJ8 ($61,830); XJ8 L ($64,330); Vanden Plas ($74,330); XJR ($79,930); Super V8 ($91,330); Super V8 Portfolio ($115,330)

Engines:300-hp 4.2-liter dohc 32-valve V8; 400-hp supercharged 4.2-liter dohc 32-valve V8

Transmissions:6-speed automatic

Safety equipment (standard):dual front airbags, front side curtain airbags, anti-lock brake system (ABS), emergency brake assist, adaptive restraint technology system (ARTS), dynamic stability control, traction control, rear park distance control