We compared Jeep Grand Cherokee engines, and the efficiency crown goes to…

Martin Pretorius

Jeep’s long-running Grand Cherokee range arrived on the international stage in 1993 with a selection of burly, American-style engines. The entry-level variant featured a 4.0-litre six-cylinder petrol mill, but power-hungry buyers could also choose one of two V8 engines of either 5.2- or 5.9-litre displacement. Today, V8s still form an integral part of the Grand Cherokee line-up, but some more-efficient alternatives have also joined the range.

Even though the second generation downsized its V8 to a mere 4.7-litres (and the 4.0-litre “six” carried over as well), buyers in export markets insisted on more fuel-efficient options. Fortunately, Jeep kept up with these demands, and introduced a series of European-sourced turbo-diesels to augment the thirsty V8s.

European examples of the first-generation Grand Cherokee used a VM Motori 2.5-litre diesel, moving over to Mercedes-Benz-derived diesels in the second- and third-generation Grand Cherokees, and finally back to Fiat/VM Motori for the . As technology improved, so did their performance, with the diesel options seeing their power climb from a measly 85 kW to today’s healthy 179 kW.

The smallest petrol is still pretty big...

Even though the old 4.0-litre engine disappeared with the advent of the third-generation Grand Cherokee, its spot was taken up by a succession of smaller V6 engines. In its current format, the 3.6-litre “Pentastar” V6 produces 210 kW and 347 Nm, and gives the big Jeep a surprising turn of speed. That’s how it should be, really, because the 3.6 V6 is still a pretty big engine by modern standards.

The real excitement comes when you specify one of the three V8 engines on offer. As the V8 entry point, the 5.7-litre “Hemi” offers 259 kW and 520 Nm. Step up to the SRT derivative, and that Hemi grows to 6.4-litres, sending 344 kW and 624 Nm to all four wheels. And for absolute insanity, there’s the recently-released 6.2-litre Supercharged Hemi in the Trackhawk, which makes an scarcely believable 522 kW and 875 Nm.

Efficiency: bigger = more power = thirstier

One thing all the petrol Grand Cherokees have in common is fairly stupendous thirst. The 3.6 V6 has decent performance, but it also exacts a toll at the pumps, with a claimed average consumption figure of 10.4 litres/100 km. However, you’d struggle to get it below the 13 litres/100 km mark in normal driving: this is a big, luxurious and heavy car with a potent engine, and moving it around takes a lot of energy.

As far as the naturally-aspirated V8s go, the 5.7 Hemi has a claimed average figure of 13.0 litres/100 km, and the 6.4 SRT has a claimed figure of 14.0 litres/100 km. However, neither of them is likely to return better than 15 litres/100 km in normal driving. As for the Trackhawk, its claimed average consumption of 16.8 litres/100 km is largely irrelevant: nobody who can afford to buy this R2.2-million rocketship will care about its thirst – not when all that power is just a twitch of your right ankle away!

Diesel takes the efficiency crown

But the real efficiency star in the Grand Cherokee range is the turbodiesel variant. This common-rail, direct-injected V6 musters a useable 179 kW and 569 Nm, which combines nicely with the 8-speed automatic gearbox (standard across the range) to endow the Grand Cherokee 3.0 CRD with a commendable claimed average consumption figure of 7.5 litres/100 km. 

During road test conditions, one such 3.0 CRD returned 8.1 litres/100 km after a week of mixed-cycle driving. This is actually remarkable for such a heavy vehicle with more-than-adequate power, and it makes the 3.0CRD the one to have, if you care about your budget at all.