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Jeep Grand Cherokee forges new benchmark for SUV performance
Bob Plunkett
Date Posted: 5/10/2005
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CHELSEA, Mich. -- Enormous logs two feet thick stack up to ten feet tall as one of many stair-stepping barriers to my 4-wheeling progress on the ultimate off-road test track for Jeep, constructed at Chrysler's vast vehicle test facility in Chelsea, Mich.
Confronted by the tall and lumpy tangle of tree trunks, a driver might prudently assume that the best way to reach beyond this blockade would be to find a path around it, but for this experiment you must drive over it.
Not just any wheels will do: For a hair-raising challenge like these big logs, it takes a Jeep, which in this instance happens to be a prototype edition of the dramatic new generational design for Jeep's finest model -- Grand Cherokee.
The big wagon represents the original sport-utility vehicle and it traces for decades in Jeep history with innovations like the Quadra-Trac automatic full-time 4-wheel-drive system with limited slip differential, introduced in 1973, and a watershed design in 1984 for the first unibody 4-door SUV wagon.
Last new Grand Cherokee design in 1992 demonstrated that a wagon SUV could conquer rugged challenges of the off-road world and still transport riders in ultimate comfort due to plush cabin appointments.
Now, this latest evolutionary scheme for Grand Cherokee -- flowing from a Detroit assembly plant which endured a $750 million high-tech expansion to produce it -- emerges for 1999 rolling on a new chassis and sporting a sleek new shell which conceals a new luxury cabin inside and new mechanical systems aboard that enable the Jeep to travel where lesser SUVs dare not venture.
It's a clear-cut case of one-upmanship as Jeep raises the level of quality and capability for SUV performance.
To prove the point, that wall of logs looms in front of my windshield as Grand Cherokee initiates an assault.
Shifting to bottom gear in lowest range of the full-time 4-wheel-drive system, this driver nudged ahead with hands squeezing a fat steering wheel, foot easing onto accelerator and mind sending a silent prayer skyward.
Then the magic began, Jeep-style, as Grand Cherokee climbed over those poles.
The wagon nosed onto the first log, tilting upward at a severe angle with front wheels articulating vertically for two feet to gain grip. Then it smothered each successive shaft in deep-tread tire rubber while also mustering an arsenal of low-gear engine torque and applying the strength of 230 horses to move two tons of Detroit steel in bump-bump-bump fashion up and across the unusual obstacle.
Grand Cherokee's low-gear torque, when coupled to a sophisticated 4-wheel-drive mechanism and rigid superstructure, allows it to perform awesome feats.
This interpretation -- consuming three years to design, test and expand a plant for construction -- looks similar in form to the previous Grand Cherokee, although the two share only a few carryover parts and the new version establishes benchmarks in capability and performance.
The structure rides on a wheelbase that's the same as before, but the length increases by four inches and roof rises two inches higher. It's 1.5 inches wider, and the track width between sets of wheels grows by an inch, although the diameter of the turning circle has been reduced by a foot for easier maneuvering in tight places.
Interestingly, the step-in height drops by an inch so riders may climb aboard with less effort, as seats rise by an inch so you end up with a better view of the road.
For rolling over off-road obstacles, chassis clearance is nine inches, or 8.7 with underbelly skid plates in place.
Sheetmetal changes were substantial to refine Grand Cherokee's familiar lines, according to John Sgalia, who manages Jeep's design studio.
An immediate impression following my first peek when covers fell off a prototype on the floor at the Jefferson North Assembly Plant in Detroit: It's the same thing, only more sleek and somehow more contemporary in form.
The familiar 7-slot trapezoidal grille separates jewel-like headlamps, and an acute slope on the hood sets up hard lines which extend to strong flat-edge wheel shoulders.
Curvy corners at the roofline soften the boxiness of Grand Cherokee.
Behind this subtle new facade, a stronger structure exists, thanks to more bracing which shapes an unyielding platform. Development of the architecture occurred through consultations with Germany's Porsche, which promotes a holistic approach to body design with all parts relating to the whole to achieve maximum effect during movement.
New suspension components are in place, including a symmetrical tri-link A-arm for the rear live axle plus refinements up front to set up car-like smoothness for pavement travel. Modified coil springs appear at every wheel with low-pressure gas-charged shocks and the tie to stabilizer bar. In front, new hydroformed control arms improve stiffness by five times to help reduce body lean when traversing rough off-pavement terrain.
Power comes from a choice of two engines.
A base plant, Jeep's worthy in-line six torque monster, displaces 4.0-liters and produces 195 hp.
A new 4.7-liter V8 option, rated at 230 hp, enhances fuel economy while lowering emissions.
Also new, a 4-speed electronic automatic transmission features high gear ratios for quick starts and snappy kick-down for downshifts.
Grand Cherokee also appears with the option of two Jeep-exclusive 4x4 systems -- Selec-Trac and Quadra-Drive.
Shift-on-the-fly Selec-Trac in part-time 4-wheel deployment functions on pavement and dirt.
Permanently-engaged Quadra-Drive, in teamwork with new Vari-Lok axles, uses Jeep's new Quadra-Trac II with hydro-mechanical speed-sensing differentials in the transfer case and both front and rear axles. Engine torque channels to the rear wheels with pavement driving or for more serious off-road work power doles out to any one or more of the four wheels which have the best traction.
The spacious new leather-lined and wood-trimmed cabin of Grand Cherokee adds comforts for luxurious travel even in the back country. With seats for five and more space inside for riders, you end up with power-everything in an elegant arrangement which sets a classy tone.
1999 JEEP GRAND CHEROKEE WAGON
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| Vehicle Specifications: |
| 1999 JEEP GRAND CHEROKEE Specs |
| Description: |
Mid-size SUV wagon |
| Model Options: |
Mid-size SUV wagon |
| Wheelbase: |
105.9 inches |
| Overall Length: |
181.1 inches
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| Engine Size: |
OHV 4.0-L I6
SOHC 4.7-L V8
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| Transmission: |
Auto/4 |
| Drive: |
Rear, 4x4 |
| Braking: |
Power 4-disc/ABS |
| Airbags: |
2 |
| Gas Mileage: |
I6: 16/21 mpg
V8: 15/21 mpg |
| Price: |
$ 27,000 to $ 37,000 |
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