Jeep 2009 Wrangler Owner's Manual - page 344
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 increased by 3 psi (21 kPa),
which equals 1 psi (7 kPa) for every 12° F (7° C) for this
outside temperature condition.
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 pressure 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 condi-
tions are such that the vehicle can be driven at high
speeds, maintaining correct tire inflation pressure is very
important. Increased tire pressure and reduced vehicle
loading may be required for high-speed vehicle opera-
tion. 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).
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