ONLY in America would they consider dropping a 6.2-litre supercharged V8 developing 707bhp into an SUV.

The result is the Jeep Grand Cherokee Trackhawk - the quickest 4x4 on the planet with a supercar bashing 0 to 60 time of just 3.5 seconds and a top speed of 180mph.

And before dismissing the Trackhawk as just another example of American excess, don't forget the Europeans have been producing hot SUVs aplenty.

Audi has made RS versions of its Q series models, Mercedes has done the same with AMG variants of its GLE and Land Rover has dipped into the pot with an SVR version of the Range Rover Sport.

But none can match the Jeep when it comes to firepower and the Trackhawk is dressed to impress too sitting an inch lower than the standard Grand Cherokee.

It also comes with quad exhausts flanking a gloss black rear diffuser, large front air ducts replacing the front fog lamps and black surrounds to the headlamps as well as a surfeit of supercharged badges.

Jeep's signature seven slot grille also gets the black treatment while inside the Trackhawk is a step up from regular Grand Cherokees with plush leather upholstery - finished in red on the car we sampled - carbon-effect trim and instrumentation that shows a plethora of performance information including g-forces, powerflow and lap timers as well as conventional trip data.

We got to grips with the Trackhawk for one lap only of parent company's Fiat Balocco proving ground in northern Italy.

The throttle power is immense. The Trailhawk blasts off like a rocket and although the steering is well-weighted the power transmitted through the wheels can unsettle it exiting corners.

Nevertheless, it handles for a big SUV with an equally massive 875Nm of torque to go at - but it has a thirst to match.

After a very hot lap at Balocco the onboard computer was showing an average of just four to the gallon.

In everyday use it's not going to be that bad but even the official fuel return is just 15.5mpg with emissions almost off the scale at 422g/km.

The Grand Cherokee Trackhawk has an uprated eight-speed version of Jeep's TorqueFlite auto box and is fitted with Quadra-Trac on demand four-wheel-drive complete with a limited slip rear differential, both of which have been modified to cope with the awesome power.

There are also six drive modes to go at including specific settings for track use, towing and a custom setting for individual preferences as well as a launch control for maximum acceleration.

In track mode the shift settings of the gearbox have been shortened by some 68 per cent to 160 milliseconds - but apart from the fact it works you'd struggle to tell that all this technology has come into play.

It's shod with 20-inch alloys, Bilstein dampers and Brembo brakes to rein in its might - the Trackhawk can cover a quarter of a mile in 11.6 seconds but has a stopping distance from 60mph in only 114 feet.

Jeep is quick to point out that the Trackhawk is as big on the safety front as it is on power and that includes some 70 systems such as a full-speed forward collision warning as well as the likes of blind spot monitors, adaptive cruise control and lane departure alerts.

The Trackhawk has already made its way across the pond from its Detroit home to Europe and is said to be coming to the UK where it's likely to cost from around £80,000.

That's a heady premium over the current Grand Cherokee but a relative snip in the high performance SUV zone where the likes of a Range Rover Sport SVR will set you back £100,000-plus.

One thing is for certain should the Trackhawk arrive in the UK, the school run will never be the same again.