Greetings Scotty!
Long time fan, you have helped me with so much, your expertise and willingness to share is appreciated by myself and many others.
I have a 1971 Ford F100 that I drive during the Spring, Summer, and Fall here in the Chicagoland area. (Garaged in winter) I drive it daily, but not very far. A few miles to and from work and some errands here and there. The truck lives in the 25-35 miles per hour range, occasionally hitting 45 or 50. Never on the interstate.
My question is about tire pressure. The truck came with when I got it (and I replaced with exact same size) P235/75R15 tires all the way around. The truck does not have any traditional tire pressure information on the door jam like modern cars. Information online varies WIDELY on what I should keep the tire pressure at in these tires on this truck. I do not know if that size tire is what was on it out of the factory 50 years ago, but that's what's on there now.
What should I be keeping these tires inflated to for the safest ride?
Thank you in advance.
-Anthony
For that vehicle, I would use 32 psi cold tire pressure.
Out of my 20+ years driving experience: optimum tire pressure may vary depending on tire make and stiffness as well as on the weight being transported. However it is relatively easy to figure out whether or not your tire pressure is correct or not on the long run for your specific conditions: if the thread is more worn out closer to the edges of the tire, than it is in the center - it is underinflation; the opposite is overinflation; even wear means optimum inflation. If you monitor your tires and notice, say, the first signs of overinflation - slight underinflation for an equal period of time may fix the problem, and then one can switch to using some in-between pressure which would probably be the optimum. Sometimes this optimum may even be different for the front and the rear tires.
