Jaguar's XJ8 represents a high point in the company's history. It is one of the finest luxury sedans built today. The Vanden Plas, named for a famous British maker of custom automobile bodies, is the most luxurious XJ8, swathed in chrome, walnut and lambs wool, while the XJR is a luxurious sports sedan.

For 2001, the sedan range benefits from more extensive emissions-control provisions.

Five versions are available: XJ8 ($56,355); XJ8 L ($62,355); Vanden Plas ($67,655); Vanden Plas Supercharged ($83,355); XJR Supercharged ($69,355).

As the XJ8 designation suggests, these are a V8-powered Jags. Two wheelbase lengths are available. The standard XJ8 and the XJR ride on a 113-inch wheelbase. Vanden Plas shares the longer wheelbase with the XJ8L, which is 117.9 inches.

Regardless of trim line, Jaguar's XJ is a beautiful car. It is stately without being stuffy, and the soft lines are uniquely Jaguar. The XJ8 continues the design theme set in 1986; Jaguar tried horizontal, contemporary-looking headlights in the 1980s, but they were so universally assailed that the company came back with round lights, and they are critical to the overall look.

The Vanden Plas shares the longer wheelbase with the XJ8L, which is 117.9 inches. The standard XJ8 and the XJR ride on a 113-inch wheelbase. Visually, that wheelbase extension is reflected in the length of the rear windows.

Ford now owns Jaguar and has brought financial support and technology to the company, which has greatly benefited the XJ8. Electrical systems, electronics and other traditional Jaguar problem areas have been eliminated since Ford got involved.

The 4.0-liter V8 has double overhead-cams and four valves per cylinder. Jaguar's AJ-V8 produces 290 horsepower at 6100 rpm and 290 pounds-feet of torque at 4250 rpm.

That impressive power is delivered to the rear wheels through a five-speed automatic transmission. This electronically controlled automatic adapts to varying driving conditions; it senses whether the driver is cruising along the highway, hot-footing down a back road or climbing a long grade and it varies shift points accordingly for optimum power and efficiency. The transmission also has a self-regulating adaptive capability; it compensates automatically for the effects of aging by adjusting shift quality based on any slippage it detects. Sport and standard modes can be selected by the driver: The standard PRNDL pattern can be used, or shifts can be made manually by moving the stick to the left.

Automatic Stability Control comes standard on all Jaguars. ASC operates at all speeds, using engine intervention to reduce wheel spin on slippery roads. If a rear wheel starts to spin, the anti-lock brake (ABS) controller signals a computer, which controls the spinning by reducing throttle, retarding ignition timing or cutting fuel to the cylinders.

An optional traction control system includes all ASC functions plus brake intervention. This system comes as part of the All-Weather package, which also includes heated front and rear seats. Both types of traction control can be switched off.

The front suspension is fully independent with unequal-length upper and lower wishbones, coil springs, shocks and an anti-roll bar. Double wishbones are also used at the rear with the driveshafts acting as upper links. They are arranged for anti-lift under braking and anti-squat under acceleration. Variable-ratio rack-and-pinion power steering is speed-sensitive.

Jaguar's uniqueness is especially evident inside. Getting in is like sliding into an English gentleman's club, with yards of supple leather, luxurious deep-pile carpeting, and polished wood on the doors, instrument panel and steering wheel. The instruments are simple and understated in keeping with the elegant mood.

Memory functions automatically adjust the driver's seat, steering wheel and outside mirror. The driver's seat moves back when Park is engaged for easy exit. It moves back to the last position that was set when the ignition is turned on. A cupholder pops out from the console, but any drinks in it tend to get in the way of shifting.

Thanks to the long wheelbase of the Vanden Plas, the rear compartment is huge and legroom is expansive. The bench seat has two depressed seating areas, but a third person would be comfortable in the middle. Airplane-like tray tables fold down from the front seatbacks. A small pod with two rocker switches on the left side of the passenger seat allows rear-seat passengers to move the seat fore and aft and adjust the angle of the seat back. Headroom is just as generous as legroom.

This year we drove the XJR. The XJR version transforms the platform, and makes the XJ8 seem sedate by comparison. The XJR is the one with the mesh grille and less trim, suiting its macho personality. The twin-cam 32-valve 4.0-liter alloy V8 is fitted with a supercharger, which boosts the horsepower from 290 to 370. The belt-driven blower is nestled between the 90-degree cylinder banks, forcefully pumping air to the intake system to increase combustion. Intercoolers chill the air to increase its density and thus oxygen content-call it O2 concentrate. The upshot is powerful and immediate throttle response, and the setup blows the XJR's torque all the way up to 387 foot-pounds at 3600 rpm. At a mere 1600 rpm, the XJR has as much torque as the normally aspirated XJ8 at its peak. Zero-to-60 time is 5.4 seconds, and the quarter-mile comes in the high 13s.

A bonus to the hot-rod performance is the very cool hot-rod sound: the whine of the supercharger when you're working it. Our test model was black, and it's the only color we can imagine for the XJR. In one package, you have elegance, brawn and, when you stand on the gas, outlaw aura. It may sound like the combination could be schizophrenic, but it's actually wonderfully symbiotic.

The XJR's shocks and springs are tuned for its role. But it isn't a car you flick, it's a car you bend. And when you bend it into the corners with respect, it responds with dignity. Its grip, measured by others on a skid pad, yields an impressive g force figure, and the Pirelli 255/40 ZR18 tires certainly contribute a lot-they are a two-inch jump from the XJ8's 16-inchers. But they also deliver an ever so smooth ride, which takes an extreme road surface or overly aggressive driver to upset. If it weren't for the fact that you'd have to be lacking a pulse to fall asleep behind the wheel of the XJR, we would say the ride and engine are so smooth they could lull you to sleep.

Imagine how much fun this car could occasionally be with a five- or six-speed gearbox. That's not to say that it needs one, because the five-speed automatic transmission is perfectly suited to the car's personality. It's another major thing that distinguishes the XJR from the XJ8. It uses the same transmission as used by the AMG Mercedes E55. In sport mode it has the capability to shift manually, after you slide out of Jaguar's traditional J-gate pattern.

The XJR also gets bigger brakes than the XJ8. The front rotors are 12.8 inches in diameter, up from the XJ8's 12.1, and the rear rotors are 8.0 inches vs. 7.2, yielding 16 percent more swept area. They'll certainly stop you quickly enough, but the pedal feel and travel is on the luxury side of sporty.

Basically, the XJR is the ultimate grownup's cruiser. It's hard not to compare it to the far less compromising BMW M5 in your head, but they're totally different beasts, and it makes you realize that "high-performance sedan" is an awfully broad description. The XJR may not be as quick as the M5 or AMG E55 on twisting road racing circuit, but the Jaguar would hold its own on banked oval like Michigan International Speedway or, better yet, the flatter Indy brickyard. At those faster circuits there would be some backing off the throttle and feeling that fantastic smooth engine roll up and down. Top speed is rated at 155 mph.

The standard XJ8 has a driving experience that's distinctive from those of the German and Japanese luxury cars. Mercedes and BMW share a ride that is more on the firm side and generally feel tight and buttoned up. Lexus and Infiniti offer a softer ride and a more relaxed atmosphere. The XJ8 is wonderfully comfortable with an elegant feel.

Acceleration performance is startling with instant throttle response. On dry pavement, the XJ8 will light the rear tires up if the traction control is turned off. Jaguar says the XJ8 can accelerate from 0 to 60 mph in 6.9 seconds, an impressive feat given its size and weight.

Shifting is silky smooth, even at full throttle. You can almost feel the transmission signaling the engine to reduce power slightly because a shift is coming. It's an almost imperceptible pause as the shift is made.

We had some fun with the manual shifting mode, but it seemed superfluous with a transmission that does such a great job on its own. The manual operation is electronically controlled to prevent downshifting at an inappropriate speed. The gear can be selected, but the shift won't be made until speed has dropped sufficiently.

Differences between Normal and Sport suspension modes are perceptible on rough surfaces and in hard cornering. The Sport setting lets a little more road roughness come through the steering, but gives the car a slightly flatter stance in cornering.

Jaguar's XJ Series is one of the finest cars built today. Ford's involvement has undoubtedly had a lot to do with that achievement. The old quality bugaboo seems to be just a memory.

BMW and Mercedes and the rest really can only be compared with the XJ8 in terms price because the Jaguar offers something altogether different.

Special tuning and greatly increased horsepower transform the XJR into a high-performance sedan.