As well as introducing the exciting new XFR at the 2009 Detroit auto show, Jaguar also decided to overhaul the XK coupe and convertible range. All the cars get revised exterior styling with a different front bumper and rear valance, rear LED lights, and color-coded side vents. Inside, Jaguar has changed the center console to incorporate its unique gear selector, a rotary control that pops up after starting the engine. The big news, however, is under hood. Both the naturally aspirated XK and supercharged XKR models receive an all-new 5.0-liter V-8 engine. Called AJ-V8 Gen III, this engine apparently shares just two parts with the outgoing 4.2 liter engine: the cylinder head bolts and the exhaust tappets.
The new engines feature direct injection and variable camshaft timing that is activated by torque generated by the opening and closing of the valves rather than by oil pressure. The naturally aspirated engine has a new variable intake manifold and camshaft profile switching in the intake cam, where there is lower lift at low rpm, helping gas mileage and torque below 3000 rpm.
The upshot is a lot more power: the naturally aspirated XK now has 385 hp and 380 pound-feet of torque, up from 300 hp and 310 lb-ft. The supercharged R has 510 hp and 461 lb-ft compared with 420 hp and 413 lb ft. Jaguar claims that the 0-60 mph time for the XKR Coupe has been reduced to 4.6 seconds. Other changes include the addition of active electronic differential control for the XKR. This system uses an electric motor to activate a clutch pack without any ABS involvement in order to optimize traction.
While Jaguar was at it, the range has been simplified to two models—the Portfolio and the R. The revised XKs go on sale this summer as 2010 models.
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