You would think that replacing the smaller, squarer Jeep Cherokee would be a more pressing need, but that one is still selling vigorously after 16 years. The competition is hotter higher up the 4x4 hierarchy, however.
There's Land Rover's remodelled Discovery to consider, and Mercedes-Benz's ML320. Add to this the fact that the old Grand Cherokee was launched in 1993, even though it didn't head here for another three years, and the product plan makes sense.
Clearly, the new car's style is influenced by the old, so much so that unless you see them together you might not spot the differences. But the new one has a wedgier profile, more rounded corners, bigger headlights and those bared fangs. This is not a discreet face, especially when it's filling the rear-view mirror of the car in front.
It's a major remake. Just 127 parts of this Austrian-built car are carried over from the old model, of which the largest is the oil filter used on the smaller of the two available engines, a 4.0-litre straight-six.
That engine is similar to the older model's, but the V8 alternative is a new, much more modern unit whose 4.7 litres produce more muscle-power than the old V8's 5.2 litres managed.
Now, you might think that all fat off-roaders are instruments of the devil. But quite apart from an ability to clamber over rocks, through mud and across sand dunes, many off-roaders are favoured transport because of their relaxed mode of progress and the fine view they give of the world beyond hedges. Here, the Grand Cherokee scores on every count.
The off-road part of its repertoire is helped by a quadra-drive system boosted by a quadra-trac II transfer case which sends its power to front and rear Vari-Lok differentials. Look behind the buzz-names, and we find a clever design which automatically sends power to the wheels with the most grip.
Most of the time, whether on or off-road, most power goes to the rear wheels. If one rear wheel starts to slither, the resultant overall speed of the rear axle becomes higher than at the front, and this speed difference causes an adjustable-pressure clutch to divert power towards the front wheels.
Similar clutches, controlled by similar hydraulic pumps, work across each axle to send power to the side with the most grip. It's all automatic, and effective enough to keep the Jeep going even if only one wheel has grip. The only transmission control, apart from a conventional automatic gear-selector, is a high-range/low-range lever.
So effective is it that, as with a really good braking system, you don't notice it's there. I took a 4.0-litre Grand Cherokee off-roading up a mountain stream, albeit with properly chunky off-road tyres, and - well, it just went up the stream. The only snag was the over-sensitive accelerator, which made for jerky progress over bumps as my right foot wobbled.
In many ways, though, the bigger engineering challenge is to make an off-roader feel good on-road. This the Grand does, thanks to a ride which feels remarkably flat and controlled for a car so high off the ground, and whose suspension is capable of such extremes of movement.
It filters bumps right away, too, so the ride is quiet and smooth. Just as good, the steering is positive in a way a 4x4's often isn't, so you don't get the feeling that you're tacking into a cross-current to take up the slack.
This quiet, relaxed motion suits the interior's ambience, which uses real leather and not-so-real wood to set the tone. The plastics feel less plasticky than before, and the independent heater controls for the cabin's left and right sides use infra-red detectors to measure each front occupant's radiated heat.
I've left the best bit to the end.
Well, it's the best bit if we're talking about the V8, for the six-cylinder is merely adequately smooth and lively, and suffers from an irritatingly indecisive automatic transmission.
The V8 is another experience entirely, surely worth the extra pounds 5,000 purchase price and the paltry 1.2mpg average economy penalty now that, unlike the old V8, you don't have to suffer left-hand drive.
Squeeze the accelerator floorwards - and feel the Jeep squirm a little and launch itself into the distance with the cleanest and crackliest of V8 throbbing noises, and you'll be starting a serious addiction. It's a civilised hot-rod, and it feels indomitable.
All the better to eat the road with, my dear.
Make and model: Jeep Grand Cherokee 4.7 V8 Limited
Price: pounds 34,995
Engine: 4,701cc V8, 16 valves, 217bhp at 4,700rpm
Transmission: four-speed automatic gearbox, four- wheel drive
Performance: 122mph, 0-60 in 8.1sec, 13-18mpg
Land Rover Discovery 4.0 V8i ES: pounds 35,070. Poshest Discovery matches Jeep's plushness but not its pace. Clever no-lean suspension makes for surprising agility
Mercedes-Benz ML320: pounds 31,780. Less powerful than Jeep, and only six cylinders, but this Mercedes is delightful to drive. Cabin feels cheap, though. Made in US
Mitsubishi Shogun 3.5 V6: pounds 39,995. Top Shogun has all the equipment but not much of the style. It's very capable off-road, though
Toyota Landcruiser Colorado 3.4 VX: pounds 34,440. Same story as with the Shogun. The Jeep is a far more desirable propositionReuse content