2008 Diesel Jeep Grand Cherokee Review

Is this the Jeep of the Future?

May. 08, 2008 By Craig Perronne
jeep grand cherokee diesel

Pros: Torque, torque and more torque.

Cons: Some squeaks and rattles. Steep diesel prices.

In Europe, the small diesel engine is king. Known for their excellent gas mileage and reliability, the micro diesels are perfect in a region where gas prices are sky high. They are found in everything from tiny trucks to luxury cars. However, on this side of the pond, diesel engines are associated with big, heavy-duty trucks. As such, they still carry the stigma of being noisy gas hogs and belchers of black smoke, but Jeep hopes to change all that with the introduction of the new diesel-powered Grand Cherokee.

Under the hood is a 3.0-liter common rail turbo diesel engine that produces 215 horsepower at 3,800 rpm along with a healthy 376 lb-ft of torque. Only the HEMI 5.7-liter engine, which is also available as an option in the GC, comes close to the diesel with 375 lb-ft of torque. However the major difference is that the diesel has an incredibly flat torque curve with all of its peak torque available from 1,600-2,800 rpm. While the HEMI comes close in overall peak torque, its curve is nowhere as flat making the little 3.0-liter diesel a naughty little torque monster.

Fire up the little diesel and it is easy to see that it is a far cry from your neighbor’s Cummins 12V that wakes you up every morning. At idle, the loud clatter typically associated with many diesels is simply not present. It’s easy to tell the Grand Cherokee is indeed powered by a diesel mill but it produces more of a murmur than a cacophony of noise. That same trend continues when under way in the Jeep. Under most conditions the diesel is near silent. Even at freeway speeds it only produces a slight growl that is no more audible than a gas engine. Only under hard acceleration is the diesel noticeable.

Besides its quiet demeanor, there was also none of the smell that is sometimes produced by diesels. No sulfur odors or diesel smell are present and the 3.0-liter also doesn’t emit a trace of smoke even under full acceleration. Like one of your kid’s few nice friends, it is quiet, clean and well-behaved.

jeep grand cherokee review

This is max flex for the Grand Cherokee. While the rear stuffs nicely there is not much movement in the front making lifting tires on the trail a common happening.

However, Jeep’s little baby-diesel also packs quite a punch. With such a prodigious amount of torque available just off idle, the Jeep Grand Cherokee diesel is a blast to drive. Simply depress the throttle and the GC goes – and goes hard. We found ourselves giving squirts of throttle to zip our way through traffic and onto the freeway. Acceleration is strong and felt on par if not better than the Grand Cherokee’s V-8 offerings. We absolutely love the power and found every excuse possible to mash the throttle to the floor. The diesel also gives the Grand Cherokee a healthy 7,400 lb tow-rating and is only a $1,600 option making it much cheaper than all of the truck diesel options.

Resting just behind the diesel is the W5J400 five-speed automatic transmission that does an excellent job. Usually transmissions can be somewhat challenged by the very the narrow RPM range of a diesel, but this one is always in the right gear. Downshifts and upshifts are timed perfectly.  The transmission also features Electronic Range Select to allow the driver to manually select each gear as well. We rarely used it as the transmission does a great job on its own.

jeep grand cherokee interior

The interior is nicely appointed, quiet and very comfortable but our test unit did emit some annoying rattles from some of the interior panels.

Long gone (and much-missed) from the Grand Cherokee are the solid axles suspended by coils front and rear. In their place is a short and long-arm independent front suspension with a rear five-link suspension. This setup is said to give better road manners (let’s face it, most GCs never see dirt) and it does to a point. The rack-and-pinion steering is way more precise than the old live axle setup and the Grand Cherokee does handle better. However the suspension felt unbalanced with the rather soft front blowing through its stroke on anything big. Not helping matters are the low-profile tires which made the ride seem firm over the broken and choppy pavement found in our urban ghetto loop.

jeep diesel review offroad

If you love giant plastic shrouds than you will love the Grand Cherokee’s engine compartment. Hidden behind the plastic is a 3.0-liter diesel that produces 215 horsepower and a healthy 376 lb-ft of torque.

In the dirt, the suspension worked well at slow speeds, letting the Grand Cherokee walk through rougher sections without tossing its passengers around. However anything above a slow clip and the GC’s suspension felt about the same as a ‘70s jeep grand cherokee dieselBuick with blown shocks. It quickly blows through its available travel and bottoms out forcing one to slow way back down. The suspension also allows little articulation meaning we often had one wheel in the air when running out of suspension travel.

Working in the Grand Cherokee’s favor off-road is the Quadra-Drive II four-wheel drive system that our tester was fitted with. It utilizes a NV245 full-time active transfer care that includes a center differential coupled with an electronically controlled clutch pack. The latter allows it to vary power front to rear dependant upon demand – and of course it can be locked as well. Also included as part of the system are Electronic Limited Slip Differentials which use electronically controlled clutch packs to automatically and instantly vary from slip to lock at each axle. In the off-road conditions we encountered, the system worked great with amazingly little wheel spin needed to engage it. Even with a wheel in the air (which happened often) we were still able to make forward progress. However, like many of today’s SUV’s, the Grand Cherokee is relatively low to the ground. Any obstacle with a decent breakover angle was a challenge for the low-slung Jeep.

The interior of the Grand Cherokee is a very nice place to spend time. Our Limited model had top-of-the-line leather seats which are both supportive and comfortable. For a smaller SUV, the GC still offers decent rear leg room and the rear seats are easy to fold flat. Our main gripe with the interior is that on graded dirt roads and rougher paved roads, our test unit exhibited a fair share of squeaks and rattles. Even the door panels would make a disconcerting noise when closing the door.

So can the diesel-powered Jeep Grand Cherokee save you money at the pump? EPA rated at 17 mpg in the city and 22 highway, we got 19.8 and 20.2 mpg over two tanks so the diesel definitely gets better mileage than its gas counterparts.

However, the problem lies is the price of diesel. Currently, in Southern California, diesel prices are usually 50 cents more than regular unleaded. Doing the math, the improved mileage of the diesel is negated by its extra cost when compared to the mileage and fuel costs of its gas counterparts. Gas prices do move somewhat independently of diesel so that may change if gas rises and diesel stays put. But even if there are no savings in fuel costs, we’re still tempted to opt for the diesel just for its gobs of low-end torque and fun-to-drive factor.

jeep diesel review

The optional HID lights on the Grand Cherokee were some of the best factory headlights we have ever tested. They provided a ton of light and vision was never a problem.

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