Cat Calls; Jaguar breeds desire with its supercharged XFR sedan and XKR coupe/convertible.(NEWS)

Byline: DUTCH MANDEL

Too few car companies follow their hearts when it comes to creating products. They prefer letting market research and consumer clinics guide them toward populating product segments.

Jaguar prefers to quench emotional desires. As a result, their cars are magic and the farthest from vanilla you will ever savor. Jaguar's latest duo, the XFR and the XKR, are two such supercharged beasts that gratify motional and emotional needs.

Jaguar starts at the core, and for these two, that means the venerable AJ-V8 engine. Com-pact and flexible, the Gen III model opens to 5.0 liters. For the XFR, that equates to a heart-thumping 510 hp backed by 461 lb-ft of torque to propel a once-dignified sedan to a smile-bending 0-to-60-mph time of 4.7 seconds. Jag's most potent touring two-door, the supercharged XKR, scampers to 60 mph a tenth of a second quicker. The top speed for both cars is limited to 155 mph, but, as proved by American racer Paul Gentilozzi, the engine is capable of much more (see sidebar).

Don't think this is a mere bore job. Only two parts carry over: a tappet and a cylinder-head bolt.

Between new die-cast heads and block, a sixth-generation Roots-type twin-vortex supercharger and a redesigned air intake that reduces flow loss by more than 30 percent, this engine uses less energy to produce its 510 hp than the existing engine used to crank out 416 hp.

Additionally, the torque curve comes on at a tick above idle, at 2,500 rpm, and stays strong through 5,500 rpm. As for efficiency, these are the only cars available ...