For a series of sedans, coupes and convertibles with 2004 designations, Britain's Jaguar rigs all models with high-tech engines and adds sophisticated safety systems plus elegant designs of high style and comfort.

Jaguar's line consists of four classes with each group having multiple variations. Classes range from the X-Type, a luxury sports sedan of compact dimensions, to the ritzy S-Types of midsize sport sedans, plus sporty XK midsize coupes and convertibles, and the XJ series of full-size sedans.

XJ cars show a new body style with the sleek package concealing a complete remake. The news here is not so much about keen performance and sporty manners, which XJ sedans possess, as it is about spatial expansion of the five-seat cockpit and the unconventional unibody structure composed of lightweight aluminum rather than weighty steel.

Early in the design process when developing a new XJ generation, Jaguar's engineers realized that a switch from steel to aluminum for the structural elements would trim considerable weight. So it does, as the aluminum-based XJ8 tips scales some 200 pounds less than the previous model built from steel. Choosing aluminum as the car's building blocks also forges a stiffer structure because it's put together with aluminum rivets and heat-cured glues in techniques lifted from the aerospace industry to create an ultra-rigid frame measuring 60% stiffer than a similar body crafted in steel.

The S-Type models were re-engineered in 2003 and return for 2004 with a six-speed automatic ZF transmission stocked in all issues and an optional Sport package available for enthusiast-oriented drivers on S-Type 3.0 V6 and S-Type 4.2 V8. S-Type R -- rolling on 18-inch low-profile tires tied to Brembo brakes and packing a supercharged version of Jaguar's 4.2-liter V8 -- gushes to 390 hp and is capable of ripping from a stoplight start to 60 mph in about five seconds.

The XK series of coupes and convertibles for 2004 use both naturally-aspirated and supercharged versions of the 4.2-liter V8 found in S-Type and XJ models, as well as the ZF automatic six-speed shifter. A special XKR Portfolio model emerges with unique paint treatment in Jupiter Red or Coronado Blue and huge 20-inch BBS Detroit alloy wheels.

And the X-Type - debuting in 2002 as Jaguar's first all-wheel-drive (AWD) car, the first compact and first Jaguar with the price tag nipping below $30,000 - returns in 2004 with two models for North America: X-Type 2.5 with a 192-hp 2.5-liter V6 engine and X-Type 3.0 with a 227-hp 3.0-liter V6. Both earn an upgraded 320-watt Alpine audio system this year and new designs for alloy wheels. (CONTINUED...)