How much from cold max psi can you vary at start of travel day??

[OregonPerson]

Hello,

I always see that you should have any ST trailer tires set to the max psi on the sidewall and try to do that. But I seem to end up 1-2 psi lower than max the next day due to losing some air when checking the pressure in the morning before heading out or a lower ambient air temperature. I then have to hook up a tire inflator to my TV just to bring them back to max psi.

Do the tires always have to be brought back up to max psi or is 1-2 psi less than max ok every so often?? I run Maxxis 8008 15 inch Load Range D at 65 PSI.

Thank you in advance.

[robkelly]

IMHO 1-2 PSI isn't going to make a difference, and I'm often in the same boat, especially if we leave very early in the morning.

[Ela1948]

In most cases a couple pounds under max pressure is just fine!! The weight of your rig determines how much air pressure should be in your tires. I upgraded my tires to E grade so that I could run 80 psi in my tires. Heat and age are the big destroyer of tires. Heat comes from tire flex when tires are under inflated or over loaded. I tend to run maximum tire pressures because it will cause less flexing.

[BigJohnD]

Load rating has everything to do with pressure. I ditched the Rainier tires and went up a load range to the 80 psi Maxxis M8008 tires. I fill them to 78 or so cold, but 75 is fine to me since I have a bit of fudge room on the weight rating. Lower than 75 and I add a little.

[vcbice]

Yep, same here. I have a TPMS to monitor tire pressure and temps, which helps my piece of mind.

I do try to keep them near 80psi cold. But, if the sun hits the tires in the morning, they will heat up a bit more than the ones in the shade, and will have higher pressures.

Same when on highway. It is interesting to watch tire temps and pressures during the day. That 78psi tire (on a cool morning) will end up near 90psi on a hot day.

[rodro123]

I keep mine at max cold pressure in truck and tt. I found this little baby and love it. Bought a couple years ago for $19 it's up a couple dollars but still worth it.
Sears.com

[Atlee]

I try to air them to 65 psi (trailer) and 55 and 60 psi (truck). If I get then to one over/under, I call it good and put everything away.