Gotta agree on not adding air to hot tires unless there is an actual decrease in pressure during the trip....and then you have a problem that needs to be found.
I check pressures in the morning when before we leave out and if we stop along the way, I'll feel the tire temps with my hand. As long as I can lay my hands on them without it burning so bad I can't keep it in place, I figure it's good. And honestly, I too believe that the internal temperature of the tire has little to do with the tread temp where it really matters. After 2 blowouts, I have become quite retentive about my tires and keep close check on them. I have had a 20-30psi increase measured during the trip by the TPMS. BUT, I also removed the TPMS because it was causing me a lot of stress as I drove and watched the temps and pressures rise of each tire. I may re-install it now that I have solid valve stems for better reliability, but so far, the last several trips have been, thankfully, uneventful!!
