For a car company, a long and distinguished heritage can be a double edged sword. The upside is that there's a vast experience curve to call upon but, less auspiciously, it can also mean that manufacturers can be hidebound by tradition. That was the problem Jeep faced when developing the third generation Grand Cherokee model. Thoroughly re-engineering the car without alienating existing customers was undoubtedly a challenge, but with a well judged series of upgrades, they may well have pulled off this tricky balancing act.

Jeep had found the market for luxury 4x4s moving rather quicker than their own development cycles. Where the Grand Cherokee was once among the premier league of Luxury 4x4s, cars like the Porsche Cayenne, the Range Rover and the BMW X5 had pushed the game to such plutocratic levels that the Grand Cherokee increasingly found itself positioned as a 'value Luxury 4x4'. The trouble was, the outgoing model felt a good deal less composed on the road than many 4x4s competing in lower categories, and its packaging wasn't as good as more contemporary compact models.

The current model addresses all of these issues. At first glance, it doesn't look a great deal different to the previous generation Grand, but park the two cars back to back and the changes are obvious. The waistline of the MK3 car is a good deal higher, giving the car a wedgier, tauter look. The headlamps are more rounded to conform with Jeep's family look. With 90mm extra in the wheelbase, this car also caters for its passengers a good deal better than its surprisingly bijou predecessor. A stiffer chassis, better aerodynamics and a proportionally longer bonnet also point to the latest Grand Cherokee's modernity.

"The latest Grand Cherokee is light years more civilised than its predecessor"

It's under the skin that the biggest changes have been wrought. Rarely will a manufacturer provide outgoing vehicles to drive back to back with the latest cars when they conduct their press events, but Jeep were keen to demonstrate the huge strides that had taken place. The old recirculating ball steering system has been replaced by a rack and pinion system and the difference is night and day. Where the old car required constant corrections to keep on the straight and narrow, the latest feels resolutely car-like, with decent feedback. It's still not what you'd describe as sporty, but it at least feels as if it's now attached to a car rather than a boat.

Hand in hand with the changes to the steering go a root and branch revision of the suspension system. Independent front suspension has helped the on-road ride and also pays dividends off-road, increasing wheel articulation and ensuring that the tyres sit squarely on the ground when the suspension is extended. Improved safety systems also feature, with stability control being fitted for the first time. This works in concert with the electronic rollover mitigation system that anticipates critical situations for the vehicle that may lead to a rollover scenario, nipping at the brakes and reducing engine torque to keep this high-sided vehicle dirty side down.

Two engines are offered, with most models fitted with the 3.0-litre CRD diesel that most UK customers want. It's a good deal more powerful than the 161bhp 2.7-litre CRD diesel fitted to the old Grand, pumping out a healthy 218bhp. This engine also marks a change in philosophy between Mercedes and Chrysler, Jeep's parent brand. Whereas in the past, many Chrysler products had to make do with what were effectively Mercedes hand-me-downs - witness the old SLK platform for the Crossfire - this 3.0-litre CRD engine is a state of the art unit, currently being installed in the factory fresh Mercedes M-Class.

This common rail diesel engine fires up with encouraging civility and only becomes vocal when fully extended. The midrange torque is predictably excellent, peaking at 376lb ft, making towing heavy loads no problem at all. It also makes crawling through tricky off road sections at little more than idle simplicity itself. Of course, there will be those who want eight cylinders and a big appetite for petrol from their 'American' car in order to feel properly authentic and Jeep serve up the proper charisma with a 6.1-litre V8. This is a powerplant that develops some 420bhp and can run on four cylinders when cruising to save fuel. Mind you, even when running on four, it's a vehicle that likes a slosh of juice. Above the standard model, trim levels run through Limited to plush Overland, with the V8 being reserved for the flagship SRT-8.

Despite the latest Grand Cherokee's civility on road, a trick Quadra-Trac II all-wheel drive system uses three limited-slip differentials to direct drive in tricky off road situations. In fact, this vehicle can extricate itself from said sticky situation when only one front wheel has traction. The underside of the car is clean, Jeep tucking the exhaust and centre and front differentials well out of harms way, even utilising the rear crash protection beams as skid sections. The front air dam is even readily removable for tough off road duty.

The danger in making the latest Grand Cherokee look so similar to its predecessor is that many buyers will think it's a facelift of a car that was becoming seriously outmoded. The truth is that with a seriously enhanced interior, more space, next generation engines, a cleverer all-wheel drive system, vastly improved road manners and a price that undercuts many comparable rivals, the latest Grand Cherokee represents a giant leap forward for Jeep.

TOP 4 GRAND CHEROKEE DEALS

The results below show the top GRAND CHEROKEE deals on buyacar

	Jeep Grand Cherokee 3.0 CRD Overland 5dr Auto SW Off Road
	ETR	Mthly £595	Saving £4,885	Price £30,810
	Jeep Grand Cherokee 3.0 CRD Limited 5dr Auto SW Off Road
	ETR	Mthly £508	Saving £4,457	Price £26,538
	Jeep Grand Cherokee 6.1 V8 SRT-8 5dr Auto SW Off Road
	ETR	Mthly £765	Saving £3,247	Price £38,973
	Jeep Grand Cherokee 3.0 CRD 5dr Auto SW Off Road
	ETR	Mthly	Saving £1,870	Price £25,225

typical 9.84% APR

PCP finance quote over 48 months,  10,000 miles pa,  deposit of £1000