Jeep 1996 Grand Cherokee Service Manual - page 1334
weather temperature varies widely. Tire pressure will
decreases when the outdoor temperature drops.
Inflation pressures specified on the placards are
always cold inflation pressure. Cold inflation pres-
sure is obtained after the vehicle has not been oper-
ated for at least 3 hours. Or the vehicle is driven less
than one mile after being inoperative for 3 hours.
Tire inflation pressures may increase from 2 to 6
pounds per square inch (psi) during operation. Do not
reduce this normal pressure build-up.
WARNING: OVER
OR
UNDER
INFLATED
TIRES
CAN AFFECT VEHICLE HANDLING. THE TIRE CAN
FAIL SUDDENLY, RESULTING IN LOSS OF VEHICLE
CONTROL.
TIRE PRESSURE FOR HIGH—SPEED OPERATION
Chrysler Corporation advocates driving at safe
speeds within posted speed limits. Where speed lim-
its allow the vehicle to be driven at high speeds, cor-
rect tire inflation pressure is very important. For
speeds up to and including 75 mph (120 km/h), tires
must be inflated to the pressures shown on the tire
placard. For speeds in excess of 75 mph (120 km/h),
tires must be inflated to the maximum pressure spec-
ified on the tire sidewall.
Vehicles loaded to the maximum capacity should
not be driven at continuous speeds above 75 mph
(120 km/h).
WARNING: OVER
OR
UNDER
INFLATED
TIRES
CAN AFFECT VEHICLE HANDLING. THE TIRE CAN
FAIL SUDDENLY, RESULTING IN LOSS OF VEHICLE
CONTROL.
For emergency vehicles that are driven at speeds
over 90 mph (144 km/h), special high-speed tires
must be used. Consult tire manufacturer for correct
inflation pressure recommendations.
REPLACEMENT TIRES
The original equipment tires provide a proper bal-
ance of many characteristics such as:
• Ride
• Noise
• Handling
• Durability
• Tread life
• Traction
• Rolling resistance
• Speed capability
It is recommend that tires equivalent to the origi-
nal equipment tires be used when replacement is
needed.
Failure to use equivalent replacement tires may
adversely affect the safety and handling of the vehi-
cle.
The use of oversize tires not listed in the specifica-
tion charts may cause interference with vehicle com-
ponents. Under extremes of suspension and steering
travel, interference with vehicle components may
cause tire damage.
WARNING: FAILURE TO EQUIP THE VEHICLE WITH
TIRES HAVING ADEQUATE SPEED CAPABILITY
CAN RESULT IN SUDDEN TIRE FAILURE.
DIAGNOSIS AND TESTING
PRESSURE GAUGES
A high-quality air-pressure gauge is recommended
to check tire pressure. After checking with the gauge,
replace valve caps and finger tighten.
TREAD WEAR INDICATORS
Tread wear indicators are molded into the bottom
of the tread grooves. When tread depth is 1.6 mm
(1/16 in.), the tread wear indicators will appear as a
13 mm (1/2 in.) band.
Tire replacement is necessary when indicators
appear in two or more grooves or if localized balding
occurs (Fig. 4).
TIRE WEAR PATTERNS
Under inflation results in faster wear on shoulders
of tire. Over inflation causes faster wear at center of
tread.
Fig. 4 Tread Wear Indicators
ZJ
TIRES AND WHEELS
22 - 3
DESCRIPTION AND OPERATION (Continued)