How temperature affects your tire pressure
The Tire Pressure Monitoring System (TPMS) monitors tire pressure in
each pneumatic tire. The pressure in each tire is dependent upon several
factors, one of them being the contained air temperature (temperature of
the air inside the tire). As the contained air temperature increases, the
tire pressure also increases. While driving in a normal manner, a typical
passenger tire inflation pressure may increase approximately 2 to 4 psi
(14 to 28 kPa) from a cold start situation. This increase in tire pressure
is due to an increase in the contained air temperature. Contained air
temperature is dependent upon several factors such as rate of tire
rotation, tire deflection, amount of braking, etc. In a similar manner, the
tire pressure will decrease if the contained air temperature decreases.
For example, if the vehicle is stationary over night with the outside
temperature significantly lower than the daytime temperature, the tire
pressure may decrease approximately 3 psi (20.7 kPa) for a drop of 30É
F (16.6É C) in ambient temperature. This lower pressure value may be
detected by the TPMS as being significantly lower than the cold pressure
indicated on your vehicles Safety Compliance Certification Label, and
activate the TPMS warning for low tire pressure. If the low tire pressure
warning light is ON, visually check each tire to verify that no tire is flat.
If one or more tires are flat, repair as necessary. Check air pressure in
the road tires. If any tire is underinflated, carefully drive the vehicle to
the nearest location where air can be added to the tires. Turn the
ignition to the OFF position. Inflate all the tires to the recommended
inflation pressure.
The Tire Pressure Monitoring System is NOT a substitute for
manually checking tire pressure. The tire pressure should be
checked periodically (at least monthly) using an accurate tire gauge,
seeInspecting and inflating your tiresin this chapter. Failure to
properly maintain your tire pressure could increase the risk of tire
failure, loss of control, vehicle rollover and personal injury.
Tires, Wheels and Loading
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