To help it stand out from other Grand Cherokees, Jeep has given the SRT8 (SRT stands for Street and Racing Technology) a muscular bodykit and 20-inch alloy wheels, while power comes from a 6.4-litre 'Hemi' V8 that produces 461bhp and 460lb ft of torque.
Cleverly, the engine can shut down half its cylinders under light throttle loads to reduce fuel consumption and emissions.
What's the 2012 Jeep Grand Cherokee SRT8 like to drive?
Despite its considerable size and 2.3-tonne weight, the SRT8 is seriously quick, blasting from 0-62mph in 5.1 seconds. In fact, it would probably be even quicker if the engine wasn't linked to a sluggish five-speed automatic gearbox.
All Grand Cherokee SRT8s come with a system called Selec-Track, which lets you adjust the firmness of the suspension along with the sharpness of the throttle responses and the behaviour of the differentials and stability control at the twist of a dial. Unfortunately, the ride is always unsettled and it becomes brutally hard if you put the car in its sportiest 'Track' mode.
With 6.4-litre V8 engine, the Grand Cherokee SRT8 is seriously quick
Your reward for putting up with this ride is good body control in corners, although you can't have a huge amount of fun in the SRT8 because it always feels like the big car it is, and the steering gives you little warning when you're approaching the limits of grip.
Wind- and road noise are well controlled, though, and the engine switches imperceptibly between four and eight cylinders. It sounds fantastic when you put your foot down, too.
What's the 2012 Jeep Grand Cherokee SRT8 like inside?
It's stuffed with standard equipment, including dual-zone climate control, heated front and rear seats, satellite-navigation, a 19-speaker stereo and a 30GB music hard-drive.
The trouble is, the cabin simply doesn't feel worthy of a 59k machine. Yes, the upper dashboard is trimmed in leather and there's some carbonfibre trim, but the switchgear and metallic-effect panels would look too cheap in a car that cost half as much.
The touch-screen infotainment system doesn't help, because it's fiddly to use and features desperately dated graphics.
However, interior space is more impressive; there's enough to keep four six-footers happy (or five at a push).
The boot is a little shallow due to the full-size spare wheel beneath the floor, but there's still room for 782 litres of luggage, which is 112 litres more than a Porsche Cayenne can swallow. As a bonus, the rear seats fold down flat at the tug of a lever.
Should I buy one?
The new Grand Cherokee SRT8 combines mean looks with stunning performance, but it will cost you a small fortune to buy and run; even with its clever cylinder shut-off technology, the engine averages just 20.0mpg.
A BMW X6 or Porsche Cayenne are better places to invest your money
If you're got around 60k to spend on a high-performance SUV, both the BMW X6 50i and Porsche Cayenne S are better buys. They're almost as fast as the SRT8, as well as better to drive, more efficient and much classier inside.
What Car? says