TM Towing Problems

[Denny_A]

Re: my 10-03-04 post regarding "cold" tire temp s/be 70 deg F.

Assumed 70 F is considered to be the temp appropriate for a 50 psi. Question is, what would be the appropriate pressure at a different temp. Assume the tire volume is constant (in a close-enuff-fer-gumint-work way), then P2 = P1*(T2/T1), where P is in psi and T is deg. Rankin. Math indicated a Temp change of 10 F should result in a 1 psi tire pressure change.

Sampled my tire pressure 3 days ago at 40 F and today at 70 F. Result:

P(@40 F) = 45 psi. P(@70 F) = 48 psi. Tire was not adjusted in any way. Temp change of 30 F resulted in a 3 psi change.

Although this was an obviously limited test, and a larger Temp difference would have been more statistically significant, it nevertheless appears to confirm the rule of thumb: Cold tire pressure changes 1 psi for each 10 deg F change.

Time to adjust my tire pressure back to 50 psi(translation: my tire is 2 psi underinflated) .

Denny_A