Tire/Rim Question

I did the same on our last trailer, went from C to D on steel rims. Ran the pressure just at or under 60psi without any problems for over 2 years before new trailer purchase. You shouldn't have a problem with this, even up to the 65psi rating of the tire. Pressures rise in hot weather, and running. Higher cold pressure usually means less tire heat and pressure rise on the road.

With the C range oem tires, I always ran them at 55psi or slightly more, again with no negatives.

Steel or aluminum rims? Most steel rims are rated to take the higher pressure.

@TUCQUALA - Awesome thanks for the quick reply. This is the first non-boat trailer I've owned so still learning. Haha.

@west - I believe they're steel. There's a 1870 lb max stamp on the inside of the rim - so that's why I was wondering about putting a 2150 tire on it.

My steel rims only have a weight capacity stamped in them not a max psi. I think it is safe to do unless there is a max psi shown on the wheel.

fla-gypsy wrote:
My steel rims only have a weight capacity stamped in them not a max psi. I think it is safe to do unless there is a max psi shown on the wheel.

Gotcha - I'll check them in the morning. Thanks!

I have a 5x10 enclosed trailer - running ST205/75R15's. The rims are rated for 1870 pounds @ 50 psi. I want to bump up to a D rated tire - rated at 2150 pounds @ 65 psi. Is there any harm in installing the 'D' tire on my 'C' rim? I'm guessing it will be fine as long as I don't pump them up to the full 65 psi - but I wanted to ask before I went ahead with the purchase.

A 5'x 10' enclosed trailer must be a single axle. I run P tires on all of my single axle trailers and tandem axle trailers under 5k-6k gross. Most P tires carry 44 psi and some go on up to 51 psi so no bead unseating worries on a lite weight single axle trailer. This way I have non of the usual ST tire issues.

The advantage of a D tire over the C tire comes at those higher pressures. Tires operate cooler when their at its max pressures.

Never over load or over pressure a wheel above the manufacturer rating. Those ratings are there for a very good reason.
Over pressure a wheel can result in the bead seat flange splitting radially with a loss of air as the tire takes on a load. BT/DT in my younger days when I was on the road.

Check out http://www.rvtiresafety.com/2013/10/will-you-increase-load-capacity-with.html from Tireman9 our resident tire engineer.

And for over pressuring a wheel read his thoughts which is common recommendations from tire and wheel manufacturers.
http://www.rvtiresafety.com/2011/12/wheel-is-just-wheel-isnt-it.html

So the rim is stamped with the weight - 1870 - but I don't see any PSI rating.

Found this on another trailer site. Not sure if this is accurate but it sounds pretty good. Haha.

"Reading back over this thread I see that a rim with 2150# of load capacity is standard Original Equipment (OE) with some of the trailers using LRC tires rated at the same load capacity. When a rim is clearly marked with it’s load capacity a PSI rating is not necessary because the load capacity of the rim dictates it’s maximum PSI rating. In other words; Any tire used on that rim can reach the maximum load capacity of the rim with 50 PSI of air pressure. Any cold air pressure greater than 50 psi will over pressurize the rim.

That statement does not rule out using tires with potentially higher load capacities than the rim. It does rule out using more than 50 psi.

Tire and rim maximum load capacities are pre adjusted for the effects of thermal equilibrium which is predictable for all tires/rims under normal conditions."

On a side note....when you change the tires, go to a light truck tire instead of a trailer tire. You'll be much happier, have more choices and less issues.

When you having your new tires mounted have them look for a psi max rating sticker on the inside of the rim (valley), I know that is where mine were for my 5er rims.