Jaguar XK models use generous amounts of riveted and bonded aluminum to save weight, yet they still weigh nearly two tons. It's tempting, therefore, to conclude that the XK isn't a sports car, it's a GT, and will not take kindly to being flung around corners at violent speed like a feather-light Lotus or a pure racecar. It turns out, the Jaguar XK manages corners with ease, provided the driver handles it with respect.
On the highway, the XK is the heart and soul of good manners. Its ride is well-tempered and lively, but free of harshness. The engine note is distant and unobtrusive, but tromp down on the pedal and you hear all manner of goodness as the V8 springs into action. There's a Snow mode that helps with traction in slippery conditions, but we learned Snow mode is also good for driving around town in dry weather to help achieve slightly better fuel economy.
In the 510-hp XKR, you're faster than almost everyone on the road. And the 550-hp XKR-S will leave some of the best sportscars in the dust. But if you really like to race people instead of simply blowing them off, the 385-hp 5.0-liter XK is your Jag. It will keep you grinning all afternoon.
Both XKR and XKR-S models are stupendously fast at the track, and at the same time, sublimely refined. Changing the modes is a bit curious: Choosing Sport mode will only change the shift points; i.e. it only affects the transmission. To tweak suspension settings and throttle response, as well as reduce the stability control threshold, one must also turn the control to Dynamic mode, designated by a little checkered flag. The exhaust note immediately gets tougher, with a roar that's well-suited to Jaguar's feline theme.
On the track, we found the Jaguar XKR-S turned in strongly and directly, with remarkably little understeer. Braking hard from high speed at the end of a straightaway, it felt like a drag-racing parachute had opened. The deceleration was violent but linear, the car hauled down from high speed by an act of will, along with grippy tires and big brakes. Downshifting with the paddles, meanwhile, caused the engine to blip automatically, matching its revs with the next lower gear.
For drifting around a wet skid pad, as we did at Las Vegas Motor Speedway, turn off the electronic stability control system altogether. Unlike some stability-control cancellation buttons, Jaguar's button truly shuts everything off. You really have to know what you're doing in this mode, as nothing will save your bacon if you don't counter-steer once that weighty rear-end starts to come around. For this reason, we'd save the Off button for special occasions in very large parking lots with nobody around but course marshalls and lap timers.