Tire heat buildup

[mbbutler]

I have TPMS. When checking cold pressures, do you compensate for heat buildup. Ex: tire rated for max load at 80psi, TPMS shows ~8psi heat buildup at 90degrees. Do you inflate cold to 80psi or 72psi?


2016 Cedar Creek Silverback 33IK
2008 Ford F-250 Crew Cab 4x4

[5picker]

ALWAYS set your max load rated pressure when cold.
Do not devalue to compensate for heat build.

[wmtire]

Originally Posted by mbbutler

I have TPMS. When checking cold pressures, do you compensate for heat buildup. Ex: tire rated for max load at 80psi, TPMS shows ~8psi heat buildup at 90degrees. Do you inflate cold to 80psi or 72psi?


2016 Cedar Creek Silverback 33IK
2008 Ford F-250 Crew Cab 4x4

Cold pressure is what you set at.

http://www.tirerack.com/tires/tirete...jsp?techid=196

Maximum Inflation Pressure

A tire's maximum inflation pressure is the highest "cold" inflation pressure that the tire is designed to contain. However the tire's maximum inflation pressure should only be used when called for on the vehicle's tire placard or in the vehicle's owners manual. It is also important to remember that the vehicle's recommended tire inflation pressure is always to be measured and set when the tire is "cold." Cold conditions are defined as early in the morning before the day's ambient temperature, sun's radiant heat or the heat generated while driving have caused the tire pressure to temporarily increase.


For the reasons indicated above, It is also normal to experience "hot" tire pressures that are up to 5 to 6 psi above the tire's recommended "cold" pressure during the day if the vehicle is parked in the sun or has been extensively driven. Therefore, if the vehicle's recommended "cold" inflation pressures correspond with the tire's maximum inflation pressure, it will often appear that too much tire pressure is present. However, this extra "hot" tire pressure is temporary and should NOT be bled off to return the tire pressure to within the maximum inflation pressure value branded on the tire. If the "cold" tire pressure was correctly set initially, the temporary "hot" tire pressure will have returned to the tire's maximum inflation pressure when next measured in "cold" conditions.

[Martsing]

Always wondered about that.

Marty

[phillyg]

You should NEVER compensate for temp rise or altitude changes. Tire mfgrs. have already done the math. Either set your tires cold for their max. pressure, or less than max pressure for your RV based on load tables provided by tire mfgrs.