Upgraded tires - air pressure?

[LoudDog]

I had load range D tires on my trailer that require 65 psi. They are the right load range for the trailer, but I wanted 10 ply so when it was time to change the tires I changed to load range E which is 80 psi.

The place I bought the tires from filled them to 65 psi (didn't notice until a few weeks later) but everything I am reading says always fill ST tires to the max.

So should I fill the tires based on trailer weight or the tire?

[ksg5000]

I don't know about trailers but in an RV/motorhome you fill the tire based on the weight of the rig. Further - I upgraded from D's to E's on my Class C - the wheel/rim of the rig has stamp indicating it's designed for lower pressure of D tire - using higher pressure might create an issue.

[Lwiddis]

"So should I fill the tires based on trailer weight or the tire?"

Fill to manufacturer specs. If you don't and have an issue...you lose...intentionally disregarded manufacturer's specs. That's one reason I stay with LR Ds...65 psi.

[LoudDog]

time2roll wrote:
Did you get high pressure stems? Otherwise yes I would run them 75/80 psi.

Would there be different stems for 65 or 80 psi?

[LoudDog]

Thanks! I had bumped them up to 80 when I caught it, but was second guessing myself.

[Sam_Spade]

downtheroad wrote:
Run them at 80psi cold inflation.

Why ? What perceived gain is there in doing that ??

The required pressure is determined mostly by the weight carried.
Stepping up one load range should NOT require more pressure to carry the load properly.

THE NUMBER ON THE SIDEWALL INDICATING THE MAXIMUM SAFE PRESSURE HAS ****NOTHING**** TO DO WITH THE PROPER PRESSURE.

[time2roll]

Did you get high pressure stems? Otherwise yes I would run them 75/80 psi.

[downtheroad]

Run them at 80psi cold inflation.

[campigloo]

I did the same thing on mine. Very glad I did. Mine has aluminum rims and there were no ratings for weight or pressure. The dealer I bought them from said being aluminum they should handle the increased pressure. I am now on my second set of 10 ply tires and no problems at 80psi.

[bobndot]

Just a thought , maybe the tire shop only put in 65# because the wheel is only rated for 65#. I don't know if the OEM wheel will handle 80# safely. ( ? )

[DutchmenSport]

I had a similar experience when I got new Carlisle's last year. They were at 65, but the side wall said max @ 80. I towed it that way a while and after a few suggestions on these forums, this spring decided to go ahead and push it to 80 psi. So far, ... um ... I really can't tell any difference.