This twin-turbo Jeep Grand Cherokee puts out 600kW.

You could hardly accuse the standard Jeep Grand Cherokee SRT8 of lacking ponies. With 347kW and 630Nm on tap, it already explores the limits of how much power a top-heavy SUV designed for off-roading should realistically have. Right?

Hennessey, of course, disagrees completely.

The American supercar manufacturer and tuner has just sent out a preview of its latest project - and it involves almost doubling the outputs of the Grand Cherokee SRT8.

With the displacement of the Jeep's 6.4-litre Hemi V8 increased to 7-litres and two turbos thrown in for good measure, the Hennessey SUV puts out 600kW and 1115Nm - enough, says Hennessey, to blast it from standstill to 96km/h in just 3.1 seconds.

The rest of the mechanics have been upgraded in accordance, the Jeep sporting lowered and stiffened suspension, 15.1-inch Brembo anchors at each end and an upgraded gearbox.

Company owner John Hennessey describes it as the ultimate snow machine: “This vehicle is designed for the performance minded driver who lives in Aspen or Moscow and wants to be the fastest in all weather conditions.”