Jaguar’s flagship XJ series is all new for 2004, and this crop of luxury sedans from the Ford-owned British automaker is bigger, roomier, and more comfortable than ever. The XJ8, Vanden Plas, and the very hot XJR are faster, safer, and also more fuel-efficient than any previous Jag.

Jaguars have always been elegant automobiles in addition to being sleek, agile, and downright sensual in many ways. Yet the Jag had its negatives as well — dependability being at the very top of that list. Fixing that — especially the notoriously vulnerable electronics — was Job 1 when Ford took over and is now just a bad memory. Another knock on the XJ was that it was too small inside.

If the new XJ were to become a true, world-class large luxury sedan, it would simply have to get bigger inside, because according to Jaguar’s demographic research, we’re all getting bigger outside. The new XJ delivers on that goal with more interior space for front passengers and dramatically increased room in the rear.

Large, sleek, and fast are words that generally don’t go together when describing cars. However, Jaguar has created a much bigger car that doesn’t look, feel, or drive bigger. And in spite of its increase in size, it’s considerably lighter and stiffer than the previous version, utilizing a body made entirely from aluminum and a sophisticated suspension with parts built out of magnesium. The combination offers a smooth ride with an impressively firm grip on the road.

The Jaguar XJ comes as three models, all with a 4.2-liter, dual-cam V8. All have the same wheelbase and stance.

There are no six cylinder XJs.

The main Jag is the XJ8 ($59,330), which of course includes a long list of standard luxury amenities and is powered by a 294-horse version of the V8 — which moves it along extremely well. The Vanden Plas ($68,330) is basically the same car with added extra luxury touches such as rugs, not carpets, and softer leather seats among others.

My personal favorite is the top of the line XJR ($74,330). It boasts a 390-horse supercharged version of the V8, along with a firmer suspension, larger Brembo brakes, and bigger wheels and tires.

There aren’t many options available because so much is standard, and some options are only available on one or two of the three XJs. For example, the very cool rear-seat multimedia center is only available on the Vanden Plas and the XJR. But what limited options there are include a DVD navigation system, special wheels, a DVD-based multimedia system, and upgraded audio systems.

The styling changes are subtle, but the XJ is quite simply a beautiful car that magically looks — depending on your viewing angle — like it’s either ready to pounce or speeding along, all while standing still.

And that look isn’t deceptive. The powerful new 4.2-liter V8 is coupled with a new six-speed ZF automatic transmission featuring a J-gate that allows you to manually shift gears if you wish. But there’s enough power and the computer-controlled gearbox does such a good job that shifting manually is pretty unnecessary.

The 390-horse XJR explodes from 0 to 60 in a mere 5 seconds and hits its rev limiter at 155 mph. The 294-horse version does the 0 to 60 drill in about 6.3 seconds — very quick for a car this size.

While some automakers try to re-invent their “look” every so often, and it’s been suggested Jaguar follow the crowd, there’s no mistaking the new XJ for anything but a Jaguar. It is an all-new car that looks remarkably similar to the old one —one of the most beautifully styled cars ever to grace the road. So if it isn’t broke, why fix it?

But if you compare this new Jag side-by-side with the previous-generation, a lot of subtle changes become immediately apparent — beginning with a grill that extends slightly forward and is styled more like the X-Type than the previous XJ. The “Leaper,” as the leaping jaguar ornament is known, sits proudly atop the hood which has Jaguar’s signature curves flowing back from the top edges of the four smallish, round headlamps.

From the rear, it’s obvious that the deck lid is much higher than ever before — again taking a design cue from the X-Type, only on a grander scale — which adds an amazing 30-percent more trunk capacity. Yet the rear styling remains simple, utilizing the traditional triangular taillight clusters.

The side view reveals a roofline four inches higher than previously, and proportionality dictates a much higher belt line which was done at least in part because people feel safer with taller doors. While this makes the side windows appear smaller, in actuality, they aren’t. With the windshield at a more raked angle than before, it appeases that sense of openness found in older Jags.

The XJ also has a longer wheelbase with the front wheels positioned further forward than before. Coupled with the subtle way the belt line inches up as it moves rearward, the car has an almost feline crouched look — as if it’s ready to pounce — even when it’s standing still.

After two decades of minimalist monotone design, chrome is making a comeback. The luxurious Vanden Plas naturally gets the most brightwork including the grille insert. The XJR boasts Jaguar’s signature R-version mesh grille, with black window surrounds, while the XJ8 has a gray grille insert. All XJs have big chrome door handles.

Each XJ comes with different size alloy wheels — the XJ8 with 17-inch light forged alloy wheels; the Vanden Plas with 18-inch cast alloy wheels; and the XJR is fitted with 19-inch cast alloys. For an even more aggressive look, optional 20-inch BBS two-piece wheels are available for the XJR.

The interior, as anyone familiar with Jags will attest, is bathed in luxurious leather, real walnut burl veneer, and little or no plastic. The combination of the look, feel, and smell is a mainstay of the car’s overall character and part of what makes it a Jaguar.

Instrumentation consists of three analog gauges clustered in front of the steering wheel. The center console houses a 7-inch LCD touch screen to manage the audio, climate, and optional navigation functions. The rows of confusing switches common in older Jaguars are history, with controls as easy to operate as possible.

Jaguar has smartly distained the temptation to load up the XJ with all kinds of gee-whiz high-tech gear ala the BMW 7-series, which has a tightly scripted start-up sequence akin to a Boeing 777. With the XJ, you don’t need to consult a three-volume owners manual to adjust the temperature or turn on the radio.

The upscale Vanden Plas boasts a plusher interior than the XJ8 that features softer leather, lambs wool carpets, and a power rear window blind. The front seats have 16 positions instead of 12. The XJR has a sportier interior with somewhat less wood trim and seats that offer extra support.

Rear passengers have considerably more room than in previous XJ8s, with a choice of a fixed-bench three-passenger rear seat. An optional rear bench has two outside seats that recline.

For rear passenger entertainment while traveling, there’s a sophisticated (around $3000) multimedia option available for the Vanden Plas and XJR. It features two 6.5-inch LCD monitors embedded in the back of the front seat headrests similar to some first-class airline seats. A control panel located in the center armrest operates them independently of each other as well as the front. For example, one person can watch a DVD while the other sees input directly from a camcorder.

Although premium sound systems are optional, the base XJ8 system is an eight-speaker setup with a single-slot CD player

Also, for the first time, Jaguar is offering the adjustable foot pedals pioneered by Ford that can be moved up to 2.5 inches at the touch of a switch. Working in conjunction with the 12 or 16-way adjustable front seat, any size driver can find a comfortable driving position.

In my view, the Jaguar experience is as much about driving as luxury. “Drivers” know that a lighter car is nicer to drive and that although comfort and lots of features are expected in a luxury sedan, they add weight. That’s why Jaguar designed an aluminum body for the new XJ. Although the new body is larger than before, it weighs 400 pounds less. Rest assured it’s as strong as steel — and aluminum doesn’t rust.

Like the fuselage of an airplane, the XJ is riveted (with about 3200 rivets) and glued, forming an immensely stiff body that meets or exceeds all safety standards. It’s also 60-percent stiffer than the body it replaced. The extra rigidity coupled with the absence of weight make a better handling car.

The XJR is quite simply the quietest, smoothest car I’ve ever driven. At 100+ mph — as I found myself unintentionally doing several times on our test drive between Phoenix and Sedona — there is almost no concept of speed. At one point north of Payson, as my driving partner and I were casually chatting away, I was startled to see the speedometer a tick away from 130. Because of that absolute smoothness coupled with superb handling, it felt like a pleasant, 70 mph drive on a slightly hilly and winding country road.

The power steering is precise without being heavy, taking the new XJ where it’s aimed. Put this big car into a tight corner at speed on a narrow winding blacktop and it tenaciously hugs the road like the cat it’s named for thanks to the double-wishbone suspension and Jaguar’s Computer Active Technology Suspension (CATS). CATS continuously and instantly adjusts the damping and works well with the air suspension, ensuring stability whether the car is undergoing heavy acceleration, hard braking, or just traversing a winding road. I found the car very stable and predictable on a variety of different roads and surfaces.

Whines: If you give me long enough, I may be able to think of something.

Bottom Line: The pure essence of Jaguar comes through in the XJ8. Jaguar has designed and built a bigger XJ delivering increased performance, improved handling, better fuel economy, and more interior space — with no trade-offs. The awesome XJR is a pure luxury sedan with wildly exhilarating sports car performance and handling. If money didn’t count, I’d personally own an XJR in a New York minute.