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stock wk crd ltd: 245/60 R 18 = 29.57471 inches
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Plus Zero 225/65-18 235/65-18 255/60-18
Plus One 235/55-19 245/55-19 255/55-19 265/50-19
Plus Two 235/55-20 245/50-20 255/50-20 265/45-20 265/50-20
Plus Three 265/40-21 265/45-21
Plus Four 265/35-22 265/40-22
from: http://www.discounttire.com/dtcs/tirePlusSizes.do?v=012592|2008&r=WASINT|pc|98204
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stock wk crd ltd: 245/60 R 18 = 29.57471 inches
18 INCH TIRES TIRE HEIGHT
285 50 18 29.22
255 55 18 29.04
275 55 18 29.91
305 55 18 31.21
235 60 18 29.10
# 245 60 18 29.57
265 60 18 30.52 3%
275 60 18 30.99
285 60 18 31.46
315 60 18 32.88 10%
from: http://www.jekylhyderacing.com/HeightofTires.htm (nuking anything less than 29.5")
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2008 Jeep Grand Cherokee SUV (base engine: 4.7L V8 FFV 4x4 5-speed Automatic)
Vehicle Model year 2008
Make Jeep
Model Grand Cherokee
Style Limited 4dr SUV 4WD (base engine: 4.7L 8cyl 5A) Base MSRP $39,305
Options on test vehicle Jeep Green Metallic Clearcoat Paint, Quick Order Package 22H
As-tested MSRP $41,055
Drivetrain Drive type Four-wheel drive with low-range transfer case
Engine type V6 Turbodiesel
Displacement (cc/cu-in) 2987 / 182.3
Block/head material Cast-iron/aluminium alloy
Valvetrain Single overhead camshaft
Compression ratio (x:1) 18.1
Redline (rpm) 4500
Horsepower (hp @ rpm) 215 @ 4,000
Torque (lb-ft @ rpm) 376 @ 1,600
Transmission type 5-speed Automatic
Transmission and axle ratios (x:1) I = 3.59, II =2.19, III =1.41, IV =1, V =.83 FD = 3.73:1, R =3.16, Low = _.___
Chassis
Suspension, front Independent, Double Wishbones, Coil Springs, and Stabilizer Bar
Suspension, rear Solid Axle, Leaf Springs, and Stabilizer Bar
Steering type Speed sensative, hydraulic-assist power steering
Steering ratio (x:1) 15.8:1-on center
Tire brand Goodyear Tire model Fortera H/L
Tire type All terrain
Tire size, front P245/65R17 105S
Tire size, rear P245/65R17 105S
Wheel size 17 X 7.5 front - 17 X 7.5 rear
Wheel material Aluminum alloy
Brakes, front 12.9-inch ventilated disc
Brakes, rear 12.6-inch solid disc
Track Test Results
0-45 mph (sec.) 4.8
0-60 mph (sec.) 8.0
0-75 mph (sec.) 12.8
1/4-mile (sec. @ mph) 15.9 @ 83.8
0-60 with 1 foot of rollout (sec.) 7.8
Braking, 30-0 mph (ft.) 36
60-0 mph (ft.) 140
Slalom, 6 x 100 ft. (mph) 58.2
Skid pad, 200-ft. diameter (lateral g) 0.74
Sound level @ idle (dB) 48
@ Full throttle (dB) 74.4
@ 70 mph cruise (dB) 67.3
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Test Driver Ratings & Comments
Acceleration comments Pretty stout launch thanks to all that torque, but the low redline means
it's over quickly and the transmission needs to upshift to the next gear at about 4,000 rpm.
Still, I enjoy the stern shove of a turbodiesel.
Braking rating Poor
Braking comments Not very confidence-inspiring from either the standpoint of its mushy pedal
or dramatic dive. While the distances didn't grow much from first to last stop (hovering around 140-145 feet),
that distance isn't particularly good in this era of car-based CUVs that regularly halt from 60 in the 120-130 range.
Handling rating Average
Handling comments Despite a non-defeat stability control (regardless of what the button and light
indicate), tire-torturing understeer is the ultimate limit on the skid pad. Steering is very light
regardless of load. Also, it was hard to maintain a steady speed because of the turbodiesel's lack
of throttle response ? very elastic feeling. In the slalom, light steering masks the heavy curb weight
only for so long. This test shows how soft the suspension is and how massive this Jeep really is.
Stability control system limits the vehicle's performance but I wouldn't want it any other way.
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Testing Conditions
Elevation (ft.) 1121
Temperature (°F) 73.6
Wind (mph, direction) 0
Fuel Consumption
EPA fuel economy (mpg) 17 City / 22 Highway
Edmunds observed (mpg) 19.3 for 900 miles
Fuel tank capacity (U.S. gal.) 22
Dimensions & Capacities
Curb weight, mfr. claim (lbs.) 4,691
Curb weight, as tested (lbs.) 4,723
Weight distribution, as tested, f/r (%) 55 / 45
Length (in.) 188.0
Width (in.) 72.6
Height (in.) 68.7
Wheelbase (in.) 109.5
Track, front (in.) 62.0
Track, rear (in.) 62.0
Turning circle (ft.) 36.7
Legroom, front (in.) 41.7
Legroom, rear (in.) 35.5
Headroom, front (in.) 39.7
Headroom, rear (in.) 39.3
Shoulder room, front (in.) 59.1
Shoulder room, rear (in.) 58.4
Seating capacity 5
Cargo volume (cu-ft) 34.5
Max. cargo volume, seats folded (cu-ft) 68.5
Warranty
Bumper-to-bumper 3 years / 36,000 miles
Powertrain Unlimited
Corrosion 5 years / 100,000 miles
Roadside assistance 3 years / 36,000 miles
Free scheduled maintenance Not available
Safety
Front airbags Standard
Side airbags Standard dual front
Head airbags Standard front and rear
Knee airbags Not Available
Antilock brakes 4-wheel ABS
Electronic brake enhancements Braking assist, electronic brakeforce distribution
Traction control Standard
Stability control Standard
Rollover protection Standard
Tire-pressure monitoring system Direct tire pressure monitoring
Emergency assistance system Not available
NHTSA crash test, driver 5 stars
NHTSA crash test, passenger 5 stars
NHTSA crash test, side front Not tested
NHTSA crash test, side rear Not tested
NHTSA rollover resistance 4 stars
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Quadra-Drive II
The Quadra-Drive II Jeep 4 x 4 system offers owners the ultimate in off-road capability.
It combines the NV245 full-time transfer case with Electronic Limited Slip Differentials (ELSD)
for best-in-class tractive performance. The system instantly detects tire slip and smoothly
distributes engine torque to the tires with traction. In some cases, the vehicle will even
anticipate low traction and adjust to proactively limit or eliminate slip
The heart of the system is the NV245 active transfer case. This transfer case includes a center
differential coupled with an electronically controlled clutch pack, varying it from a completely
open state to completely locked, and infinite possibilities in between. The 4-Low gear ratio is 2.72:1.
Quadra-Drive II features an electronic shift mechanism with a unique engagement lever. The lever is
conveniently located on the shift console. Pulling the lever up engages 4-Low. The lever returns to a
resting position after activation. The transfer case also includes a neutral position for trouble-free
towing vehicles, such as behind a motor home.
A key component in the Quadra-Drive II system is the ELSD – an industry first application – and the
new benchmark for automatic traction differentials. The ELSD use electronically controlled clutch
packs to automatically and instantly vary from slip to lock at each axle. This maximizes traction
when needed without any of the on-road drawbacks normally associated with such a robust 4 x 4 system.
All components of the system work together, continually monitoring needs, to provide smooth and
automatic application of the components for best-in-class tractive performance while improving
the day-to-day on-road driving experience. For example, the ELSD releases the clutch packs in the
front axle during turns to allow differentiation and prevent crow hop.
Eaton ELSD
Rear axle ELSD. The Eaton EGerodisctm is a hydraulically-operated electronically controlled
limited slip differential that is capable of providing variable torque up to full axle lock
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