Should 225/75R15 Tires Be Ran at Full PSI with Trailer Unloaded

Published 08/20/2024

Question:

Good morning, I just purchased a brand new RV trailer and want to make sure I do the right things. My RV comes with ST225/75R15/D tires, just one axle, with recommended cold tire pressure of 65 PSI / 448 KPA. RV dry weight is 3,584 lbs, and maximum weight (GAWR) is 4,955 lbs. Reading previous answers to other fellows, I understand that you recommend to have the tires always at 65 PSI, maximum cold tire pressure, instead of reducing tire pressure according to weight?? I'm I right?? Please let me know, many thanks in advance and regards

asked by: Juan

Helpful Expert Reply:

Hey Juan, thanks for reaching out!

You've stumbled upon one of the greatest frustrations in the trailer tire industry. The everyday user knows that it's okay to lower the psi in the tire some so that it isn't as stiff and bouncy when the trailer isn't loaded to max weight, but most of the tire companies on the market don't have a chart showing what the weight rating is for different psi ratings.

So, for a 225/75R15 tire like the Karrier # AM10256 we see the 2,540 lbs at 65 psi rating but Kenda doesn't say it's okay to run the tires at a lower psi.

Because of this our hands are kind of tied. We can't safely say to run the tires lower, but we know it's a common practice, so we're basically left to say lower the psi at your own risk.

I know it's not a great answer, but unless the tire company has a chart showing the different ratings at different pressures (like what the Goodyear tires do) then this is what we have to stick by.

expert reply by: Jon G