Tire pressure

If you want your tires to be capable of carrying their maximum weight, inflate to the sidewall maximum pressure. Few dealers are careful with the/qualified to determine weight and the correct tire pressure. The “lot boy” doesn’t care.

Weight of your trailer on axles divided by number of tyres = xxxx find tyre pressure chard for your tyres and it will tell what pressure to run them at.
Frank

I read this on etrailer.com ——->

You always need to keep your trailer tires filled to the max cold psi rating. If your current load range G tires have a 110 psi rating then that is what you need to keep them filled to.

Tire blowouts are a result of damaging a tire (like hitting curbs), under or overfilling a tire, exceeding the speed rating for the tire, exceeding the weight limit, or even messed up suspension parts.

For example, the Provider ST235/85R16 Radial Trailer Tire # TTWPRG235R16 has a load range G which is 4,400 lbs at 110 psi for a single tire application like what you have. It also has a speed rating of M which is 81 mph. If you don't have the tire filled to 110 psi then it will get hot quickly and can cause a blowout. Most trailer tires have a speed rating of 65 mph so if you were exceeding that speed limit then that would also explain the blowout.

If you don't know the weight of each wheel then you should run 110 psi. unless you know they are way oversized tires for the RV.


If the GVWR is over 15K I would run 110.

WrightOn wrote:
My new to me unit has Load Range G tires that indicate 110 psi cold max. I used it last year over 2000 miles at 80 psi as that was the pressure leaving the dealership. I’m headed out from Illinois to Maine this week. Do I jack them up to 110, keep them at 80, or somewhere in between?
Thanks for your help.
Brian

Per Goodyear:

"Unless trying to resolve poor ride quality problems with an RV trailer, it is recommended that trailer tires be inflated to the pressure indicated on the sidewall of the tire. Trailer tires experience significant lateral (side-to-side) loads due to vehicle sway from uneven roads or passing vehicles. Using the inflation pressure engraved on the sidewall will provide optimum load carrying capacity and minimize heat build-up."

Reams of information here by a tire engineer supporting sidewall cold inflation pressure as being optimum to reduce interply shear.

http://www.rvtiresafety.net/search/label/Interply%20Shear

You need to know how much weight you have on your tires before you know what to inflate them to. They will not get hot quickly and cause a blowout if you don't have them inflated to 110 psi. I have a triple axle toyhauler with 12,000 lbs. on all three axles, with a max of 2500 lbs. on two tires. I run my G-rated Sailun tires at 90-95 psi., and have been doing so for nearly 5 years. My Sailuns show even wear and look to be good for several more years.

But you need to know how much weight you're carrying on your axles. Knowing how much weight you're carrying on individual tires is good, but sometimes that can be a hassle to get.

Personally I feel uncomfortable running my G-rated Sailuns under 90 psi, but I do know some who run pressures down in the 80's. But not me, in the summer I run 95 psi as a rule. 110 psi is too much pressure for my weight and beats me, and my trailer, to death on rough roads.

X2, rwake.

I concur with those who say to air them all the way up. I wouldn't trust Chinese tires as far as I could throw them, but if I absolutely had to, I'd want to give them every imaginable chance to shed heat. I'm sure someone will be here to tell me how great these particular Chinese tires are, to which I am happy to tell them that it's a big market and to enjoy their purchase.

I run Michelin XPS Rib truck tires on my toy hauler. The tires are 5 years old and I've never run max psi in them, usually around 70 psi. The way I see it, my truck runs 70 front and 65 rear per the sticker, not the max pressure on the sidewall. My car runs 30 psi per the sticker, not the max pressure in the sidewall. I don't run max psi on my Harley. Why should my trailer be any different? Well built tires don't need to be babied for fear of exploding from heat, which is why I'll never buy trailer tires.

The trailer tire people say to run max air in the Chinese-made tires because they are total junk and will fail if they get much above room temperature. :)

azdryheat wrote:
Why should my trailer be any different?

Because it is a different type of vehicle with different types of forces impacting the tires. With tires on multi-axle trailers, like RV trailers, the belt (interply) shear forces can be 24% higher than the belt shear forces of identical size, load and inflation tires on a motorized vehicle.

The internal structural forces are different for torque than for high "slip angle" which is the situation in trailer application. Front tires on cars, motorhome or tow vehicles experience slip angle usually in the 1° range while trailer tires are subject to angles in the 10° and greater range. The forces are NOT linear. 10° can generate significantly more shear than 1°.

Here is a large amount of data compiled by tire engineers regarding this issue: http://www.rvtiresafety.net/search/label/Interply%20Shear