Jeep Grand Cherokee

Where its predecessor showed its age, this new Jeep is a modern and impressive SUV. The aggressive US styling stands out from the crowd, and as long as the low-grade plastics are improved for the UK, the car is hard to fault. Ride, handling, performance and refinement are excellent and with the 3.0-litre CRD motor, there's economy, too.

New from the ground up, it has a range of fresh engines and a cutting-edge drivetrain, plus bang-up-to-date styling. So has Jeep's biggest model broadened its appeal? Three versions will be available in June, with a fourth arriving by summer 2006. Making up the quartet next year will be a mighty 6.1-litre petrol-powered SRT-8 flagship. But the biggest seller from the outset will come with a 3.0-litre diesel engine.

Shared with Mercedes' new M-Class, it has been tuned for more power and torque to improve acceleration through the gears. This unit is so good that it will account for 85 per cent of Grand Cherokee sales - and it is not difficult to see why.

Offering more torque than either of the V8 petrol engines which are available from launch, the refined oil-burner is teamed with a smooth five-speed automatic gearbox. And for optimum on and off-road grip, Jeep has developed a new transmission set-up called Quadra-Drive II.

Thanks to electronically controlled limited-slip diffs front and rear, the car will never get stuck, even if there is traction to only one wheel. Electronic Stability Protection is also now standard, so if the Jeep enters a corner too quickly, drivers can fall back on the system to correct a slide without brutally cutting the power.

This is an SUV which needs to handle well no matter what the surface. While our drive off-road showed how capable the car is when the going gets rough, it is on the tarmac that the Grand Cherokee really impresses. Excellent body control, a supple ride and strong, progressive brakes are backed up by steering which is sharper than ever.

Buyers who prefer petrol power will initially be given a choice of two engines, each using the same transmission as the diesel. Carried over from the previous Grand Cherokee is the 231bhp 4.7-litre V8, while those who want more muscle can also opt for a 5.7 HEMI unit that pushes out 326bhp and 500Nm of torque.

While neither petrol unit is frugal, the smaller one has been tweaked to give a seven per cent improvement in fuel economy over its predecessor. It still manages only 19mpg, though. However, it is the 5.7-litre car that diehard Jeep fans will aspire to. The trouble is that even with the benefit of MDS (Multi-Displacement System), which closes down up to four cylinders when cruising, combined economy of this £37,995 model is a mere 18mpg. Unfortunately, this is not the only flaw. While the Jeep is well designed, drives well off-road and on and has a practical five-seat interior, it is let down by the quality of the cabin plastics.

We have been promised that the cheap materials used on our early test car will be upgraded before the first UK customer models are delivered. If the firm is true to its word, the new Grand Cherokee is sure to continue Jeep's long-standing rivalry with Land Rover.