Whereas the old Grand Cherokee used a Jeep chassis and a Mercedes engine, this one has turned the concept on its head by borrowing the platform from the 2012 Mercedes M-Class and powering it by its own engine, or at least one produced for Fiat, the majority shareholder in Jeep’s parent, Chrysler.
It is tempting to park the credit for all the manifest improvements enjoyed by this Jeep at Mercedes’ door, but the fact is that it’s still perfectly possible to make a pig’s breakfast out of someone else’s perfectly good platform, as Volvo has demonstrated on and off for some years.
Even so, the simple stat that this Grand Cherokee is – and this is not a misprint – 146 percent more structurally rigid than the last gives some idea of how far up the engineering ladder Jeep has been able to climb. Why does this matter?
Without a stiff chassis, your suspension can’t work so the car will neither ride nor handle and your NVH (noise, vibration and harshness) will run out of control. A run around the block in the old Grand Cherokee would illustrate this point nicely.
The engine is interesting. Built by VM Motori and apparently developed by Fiat, it has not only exactly the same 2987cc capacity as Mercedes’ 3.0-litre V6 but precisely the same bore and stroke, too, so we’re guessing not too much re-engineering of the platform was needed to make it fit.
But this apparently state-of-the-art engine was originally hobbled by the need to run through a five-speed automatic transmission. Given that, its emissions and economy figures are even more impressive than is initially apparent.
That engine will account for the vast majority of Grand Cherokee sales in the UK. However there are always a few people who cannot help but spend as much as is possible on a car they like regardless of how inadvisable that might be. Hence there is also the SRT8, equipped with a 6.4-litre V8 petrol engine, making 461bhp and priced at the best part of £68,000. Forgive us if we fail to major on this during the rest of the test.
Jeep has not followed its softer rivals in ditching the low-ratio transfer box, but height-adjustable air suspension – essential for anything more than the lightest of off-roading – doesn’t feature on the entry-level model. Manually locking differentials aren’t available, either. Nevertheless, different off-roading modes are selectable via a rotary ‘Selec-Terrain’ dial. And if you think that this sounds like Jeep is taking a leaf out of Land Rover’s ‘Terrain Response’ book, we do, too.