09-07-2016, 12:36
Hi Ross,
For grins, the ideal formula is P1T2=P2T1, temperatures in kelvin.
For example:
In the morning when it's 80 deg F (300 deg K) you set your 315 pressures to 130 psi and you get on the road, the day warms to 100 deg F (310 deg K) and the work done by the tire warms the tire an additional 50 deg, so your tires are now at 150 deg F ( 340 deg K).
Solving for P2 your runtime hot 315 tire pressure will be (340/300)*130 = 147 psi,
and with the 365's the runtime hot pressure is (340/300)*110 = 125 psi
Add in some sun baking, stops and brake heat, turns and hub bearing friction and we're pretty close to what you are seeing. Looks normal.
For grins, the ideal formula is P1T2=P2T1, temperatures in kelvin.
For example:
In the morning when it's 80 deg F (300 deg K) you set your 315 pressures to 130 psi and you get on the road, the day warms to 100 deg F (310 deg K) and the work done by the tire warms the tire an additional 50 deg, so your tires are now at 150 deg F ( 340 deg K).
Solving for P2 your runtime hot 315 tire pressure will be (340/300)*130 = 147 psi,
and with the 365's the runtime hot pressure is (340/300)*110 = 125 psi
Add in some sun baking, stops and brake heat, turns and hub bearing friction and we're pretty close to what you are seeing. Looks normal.