Jeep diesel: Eisbein in a Big Mac
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We've seen "powered by Mercedes-Benz" on the back of SsangYong Mussos for years, now. But on the back of Jeep's top-line Grand Cherokee? And the latest engines to boot? Yesiree!
Of course, you can't actually read the writing, 'cos it's not there on the Jeep. And when you read all the brochures, it doesn't actually SAY it's a Mercedes engine.
But the fact is, it's as close to being a real Merc engine as the MINI motor is to a Chrysler Neon 16's. In other words, from the same factory!
We're talking, of course, about Jeep's greatest triumph, the Grand Cherokee 2.7 CRD, a turbo-diesel wonder that is the antithesis of the VM Motori oiler used in the previous Jeep GC. The Mercedes engine is smooth, it's powerful - from REALLY low down the rev range - and it's economical.
What more could you ask for? Well...the car is on the top side of South African 4x4 pricing - albeit coming in lower down the scale than less-sophisticated offerings from Land Rover and Toyota.
It's also less boxy than any of its opponents, and off-road is superbly capable, its Quadra-Drive system the envy of all its opponents - and it doesn't need electronics to make it work.
In fact, I've seen a Grand Cherokee inch its way up a streaming wet, smooth, and unwalkable rock slope, constantly transfering power from one wheel to another as it found some grip, until it finally got to the top.
And no huffing, puffing, or the emission of strange and unpleasant smells from the brakes and clutch.
Thick sand
On the other side of the coin, I've personally driven through the thickest sand, up to the wheel centres, without even having to let the tyres down to get more grip, while everybody else was fighting the steering wheel, playing with the engine, and having a thoroughly miserable time.
I, meanwhile, was able to chat to my passenger and enjoy the scenery. And I didn't have to re-inflate the tyres.
It's all down to the Quadra-Drive four-wheel drive system. This is actually a combination of the second generation Quadra-Trac II transfer case and Vari-Lok progressive front and rear axle differentials. Under normal driving conditions 95% of the engine's power goes to the rear wheels.
The moment a wheel loses traction, a speed variation occurs between the front and rear axle causing a shift in power to the front wheels.
This same system can also respond to traction losses from side to side, meaning that even in a situation where only one of the four wheels has traction, the Quadra-Drive will deliver power to just that wheel.
This all happens in an instantaneous, seamless manner with no driver input required.
For serious off-road work, shifting the Quadra-Trac II transfer case into low range gives a torque multiplication of 2.72.
But I digress. Enthusiasm does that to me sometimes.
We were very excited when we tested the Grand Cherokee 4.7 LTD just over a year ago. It is smooth, and powerful, and comfortable and sophisticated, all in one.
Fuel consumption
But fuel consumption was horrendous, spoiling the pleasure of an otherwise super 4x4.
The 2.7 CRD is a horse of a different colour, however.
Inserting the Mercedes five cylinder twin-camshaft four-valve engine with the variable geometry turbocharger under the Jeep bonnet wasn't THAT simple, even with lots of room to play with, for the Jeep engineers had to modified the turbo itself, both manifolds, and various other items to suit their own requirements.
And the Mercedes-Benz 5-speed automatic gearbox had to be altered to make it fit the Jeep 4x4 hardware and transfer case.
But what a difference. Now you can just leave it in auto and let it waffle around the countryside. Or you can use the sideways "tip" shift to lock up the gears wherever you choose, which makes clambering down a mountainside easy, stress-free, and most of all, safe.
It also helps that you can choose your gear - and stay in it - when going up loose stuff, where a higher gear is usually preferable to a kickdown into a lower, and more spin-prone, ratio.
For the UK, Europe, and of course, South Africa, the Grand Cherokee is manufactured at Graz in Austria. Chrysler says the CRD "demonstrates the optimal balance of American emotion and European rational values", and there's a lot of truth in that.
The CRD may have the smallest capacity (2 685 cm3) and lowest power output (120 kW at 4 000 r/min) of any Grand Cherokee, but in terms of peak torque it actually has the same 400 Nm as the 4.7-litre V8 in the LTD, and at lower revs, to boot.
This means it bounds along tar roads with ease at our legal speed limit and beyond, with nary a growl out of place or an unnecessary roar. And on the rough stuff, well with that peak torque at a lowly 1 800 r/min, it will potter along over rocks and through sand (as mentioned) without even missing a beat.
The biggest thing, though, is fuel economy. Don't get edgy if you get 10 litres/100 km around town, or even down to 11 litres/100 km in low range off-road.
Open road
You'll make it up on the open road, where you can expect it to plunge to a filling station defying 9.5 or even 9 litres/100 km if you keep your speed at a pace that keeps the cops happy.
Dynamically, however, you won't feel for one minute that there's more than a Mercedes engine in the turbo Grand Cherokee.
Compared to its cousin, the Mercedes ML 270, it's chalk and cheese, with the German (designed - but built in the USA) product aimed at the soft-road market, with superb on-road manners tempered by a shortage of off-road ability compared to the rugged-looking Jeep.
The Jeep barrels along the straights, and there's no denying that a Grand Cherokee has praiseworthy stability on a motorway in high winds. But there's no comparison in ride quality or cornering, either in one bend or through a series.
The Jeep was designed principally for American roads, the M-Class, although it's built in Alabama, for European conditions.
The same applies to the interior trim. Much roomier than the smaller Cherokee, the Grand Cherokee 2.7 CRD model comes only in the Laredo specification, which means deeply upholstered cloth-faced seats, 17 inch alloy wheels, a comprehensive instrument panel with speedo, revcounter, water temperature, oil pressure, fuel, and oil temperature gauges.
The air conditioning is upgraded in this latest Grand Cherokee, and the dual front airbags supplemented by new side curtain airbags.
From a driver's perspective the Grand Cherokee offers improved seats, increased soft touch material and a more logical control layout.
Steering wheel buttons for the audio system and cruise control mean less searching for the radio station or next track button on the CD, and make steady speed cruising a cinch.
There's also an overhead console for programming such things as door lock behaviour or headlamp delay. Want all the doors to lock above 40 km/h, or how about locking the car and walking away with the headlights still on? Is that the designated headlamp delay, or were they left on by mistake?
These are just some of the features that are easily changed or eliminated via the programmable Vehicle Information Centre in the overhead console.
And if you're into gimmicks you can brag about infrared dual climate controls and a low fuel chime (both of which work quite well, mind you).
There's some aluminium trim to take the edge off the fairly plain interior.
Space is excellent - much improved by sending the spare wheel under the luggage - and it's a good looker that combines the right amount of brawn with chic.
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