Tire Pressures For High-Speed Operation; Radial-Ply Tires - Jeep Wrangler Owner's Manual

Inflation pressures specified on the placard are
always "cold tire inflation pressure." Cold tire
inflation pressure is defined as the tire pressure
after the vehicle has not been driven for at least
three hours, or driven less than 1 mile (1.6 km)
after a three-hour period. The cold tire inflation
pressure must not exceed the maximum infla-
tion pressure molded into the tire side wall.
Check tire pressures more often if subject to a
wide range of outdoor temperatures, as tire
pressures vary with temperature changes.
Tire pressures change by approximately 1 psi
(7 kPa) per 12° F (7° C) of air temperature
change. Keep this in mind when checking tire
pressure inside a garage, especially in the
Winter.
Example: If garage temperature = 68° F (20° C)
and the outside temperature = 32° F (0° C) then
the cold tire inflation pressure should be in-
creased by 3 psi (21 kPa), which equals 1 psi
(7 kPa) for every 12° F (7° C) for this outside
temperature condition.
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Tire pressure may increase from 2 to 6 psi (13
to 40 kPa) during operation. DO NOT reduce
this normal pressure buildup or your tire pres-
sure will be too low.
Tire Pressures For High-Speed
Operation
The manufacturer advocates driving at safe
speeds within posted speed limits. Where
speed limits or conditions are such that the
vehicle can be driven at high speeds, maintain-
ing correct tire inflation pressure is very impor-
tant. Increased tire pressure and reduced ve-
hicle loading may be required for high-speed
vehicle operation. Refer to original equipment
or an authorized tire dealer for recommended
safe operating speeds, loading and cold tire
inflation pressures.
WARNING!
High speed driving with your vehicle under
load is dangerous. The added strain on your
tires could cause them to fail. You could have
a serious accident. Do not drive a vehicle
loaded to maximum capacity at continuous
speeds above 75 mph (120 km/h).

Radial-Ply Tires

WARNING!
Combining radial ply tires with other types of
tires on your vehicle will cause your vehicle to
handle poorly. The instability could cause an
accident. Always use radial tires in sets of
four. Never combine them with other types of
tires.
Cuts and punctures in radial tires are repairable
only in the tread area because of sidewall
flexing. Consult your authorized dealer for ra-
dial tire repairs.