I'm about to leave on a 2 week roadtrip and I have a question about proper tire pressure. Normally, I keep my tires at a fairly high psi (42 front, 40 back). I know that tire pressure naturally rises as the temperature does. My question: do I need to lower my tire pressure at all before setting out on my roadtrip, or will 42/40 still be okay even with the long mileage and high temps? Thanks for your insights!
No need to lower you pressure for a couple of reasons. The max pressure on your sidewall is pressure for a tire at ambient temperature, the tire manufacturers have already take into consideration the fact that pressure increases with temperature. And, the higher the pressure the cooler the tire runs because it flexes less. It's is tire temperature that destroys tires in hot weather, not pressure. You are better off at your 42/40 in 100++F weather than you would be at a lower pressure.
The tire pressure ratings are based on cold temperatures and allow for expansion. As long as your cold tire pressure is below the maximum tire rating you will be fine.
