Feature > New Vehicle Reviews
2005 Jeep Grand
Hemi Power and Suspension Refinements Add up to an Even More Versatile 4x4
story by Steve Temple
photos by the manufacturer
The setting for our first exposure to the new Jeep Grand Cherokee wasn’t exactly the rugged terrain that this vehicle would normally tackle. It was carefully placed on an impeccably manicured polo field as flat and green as a pool table. With a stately mansion serving as a backdrop to these high-society surroundings, we began to feel a bit under-dressed in our jeans and hiking boots, expecting a butler to show up at any moment with a caviar tray and flutes of champagne.
Maybe we received the wrong invitation. After all, we didn’t come here to sip wine with a company whose vehicles have made their reputation running the Rubicon. Not that there’s anything wrong with this posh treatment (hey, we could get used to this, ya know), but it’s hardly the stuff of a wild and wooly off-road adventure.
Not only that, we had heard that 2005 model had been revised to improve its on-road performance. Had our beloved Grand Cherokee sold out and gone uptown in trying to compete with all those blueblood SUVs?
After all, back in 1992 when the Cherokee first rolled out, there weren’t many SUVs on the market. But now, it has to contend with an excess of high-quality competitors, all of which deliver a cushy ride, a more carlike interior, and loads of amenities. Maybe the pressures to conform to civilized society were just too intense...
Turns out our initial impressions were all wrong. True, the lines of the vehicle are now a bit more stately (like that mansion in the backdrop, displaying a bit of Land Rover flavor in the squared-off rear quarters). And the front suspension is now fully independent for a more responsive ride on the road. Add to that a sophisticated 5.7-liter Hemi V-8 as an option, and you have an SUV that can hold a fork as correctly as any of its more cultured cohorts.
But our down-and-dirty buddies from Jeep didn’t let us down. After a detailed technical presentation on the merits of the new design, they led us away from the Prince Charlie polo field, and we headed for the hills north of Santa Barbara, California. The trail we took purposely led us straight into a nasty stretch of impossible inclines and washed-out gullys. The gnarly chutes would clearly test the mettle (and metal) of the new chassis.
How is it different? As explained to us by the techies, the 2005 Grand Cherokee is stiffer, with a 60 percent increase in torsional rigidity. It’s also longer and wider than the previous model, but not as big as midsize sport utilities with third-row seats. The latter feature is noticeably omitted in this new model’s richly appointed interior, which is also outfitted with the latest electronics for navigation, communication and entertainment. Jeep’s research indicates that owners of sport utilities with three rows of seats seldom use the third one. (Jeep is planning a future sport utility for 2006 with three rows of seats.)
The Cherokee’s wheelbase has grown four inches to 109.5 inches, and its overall length by nearly six inches to 186.7 inches. Its track has widened by nearly three inches to 62 inches. The longer wheelbase and wider track are intended to improve the stability of the SUV and make the ride more comfortable.
As for the suspension, Jeep engineers sought to refine the ride and handling with a new independent front suspension (dual A-arms with coil-overs). The previous model had a three link rearend, but the ’05 design features a five-link setup with live axle, link coil with track bar), along with rack-and-pinion steering. To ensure the Grand Cherokee’s preserves its legendary off-road prowess, the Grand Cherokee offers three new full-time four-wheel-drive systems.
Going from the simplest to the most sophisticated, the Quadra-Trac I uses a single-speed NV140 transfer case to provide convenient full-time four-wheel drive with no action required by the driver. Moving up the scale, the Quadra-Trac II builds on this system with a new NV245 transfer case that provides full-time, active four-wheel drive, which anticipates and prevents tire slip in slippery conditions. This system features a two-speed transfer case with a low-range ratio of 2.72:1, along with neutral for towing.
For even more advanced off-road capability, the Quadra-Drive II 4x4 system combines the NV245 full-time transfer case with Electronic Limited Slip Differentials. The ELSD at the front/rear/center employs electronically controlled clutch packs that can automatically and instantly vary from full differentiation to full lock at each axle.
Also available is an Electronic Stability Program (ESP) from Mercedes-Benz, designed to help the driver maintain control by selectively applying individual wheel brakes and adjusting engine torque.
A new Dynamic Handling System (DHS), should be available by the time you read this article. Although not available for our trail ride, we did test it on pavement in a slalom course where its effect is more obvious. This innovative feature employs an active stabilizer bar controlled by hydraulics. On the road, it’s designed to minimize body roll with actuators that pressurize the end links of the sway bars. But on uneven terrain it uncouples the actuators, allowing for fuller suspension articulation (and less sideways head toss).
Traditionally, a stiff stabilizer bar improves handling, but diminishes ride quality, especially on uneven terrain. Jeep’s DHS overcomes this problem by engaging the front and rear stabilizer bars only when necessary, as determined by several electronic sensors. Putting it conversely, you might think of the DHS as eliminating the need to manually disconnect your swaybars before heading off-road, because in 4-Lo, the system is disabled. On the pavement at speed, however, we found that the DHS nicely settles down the chassis during hard cornering maneuvers.
The vehicle that we ran through the gauntlet of gully washes had the Quadra-Drive II 4x4 system (but without the DHS, as noted above.) It’s frankly amazing how easily it tracks along in the most challenging conditions. Like a good trail horse, you can basically just give it its head and this Jeep will find its way home. The Grand Cherokee makes it easy even for a novice ‘roader to negotiate the tough stuff.
The extra grunt from the Hemi V-8 certainly makes a difference (about 25 percent more, to be precise, compared with last year’s model). Delivering 330 horses and 375 lb./ft of torque, this aluminum-head engine with hemispherical combustion chambers not only has the power to pass at will, but also climbs effortlessly up and over obstacles. Some 90 percent of the peak torque available between 2900 to 5100 rpm.
Even more surprising is the fuel economy, because the Hemi provides cylinder deactivation through a Multi-Displacement System (MDS). By means of MDS, the Hemi can alternate between running on eight and four cylinders in a mere 40 milliseconds. It’s a rare example of how not running on all eight cylinders can be smart.
That’s because the Hemi’s EPA mileage rating is only one mpg less than the 4.7-liter V8 (20 versus 21). And the Hemi’s highway mileage is actually the same as that of the 210hp V6 that’s also offered! Given the Hemi’s one-two punch of performance and efficiency, it’d be hard to turn down the extra expense of this enticing engine option (which also includes the Dynamic Handling System). We’d also recommend the off-road package that includes tow hooks and chassis skid plates.
Another feature that simplifies off-road performance of the Grand Cherokee is the 5-speed automatic tranny that has an Electronic Range Select (ERS) system. (Don’t feel bad if you’re having trouble keeping up with all the acronyms on this new model, because you’re not alone.) In addition to a fully automatic mode in the Drive position, the ERS allows the driver to manually choose each gear simply by tapping the shift lever either to the left or right. An electronic display on the instrument panel indicates which gear you’re in, so you don’t have to take you’re eyes off the trail — nor the polo ponies — for that matter, because this new Jeep is right at home in either setting.