What should the PSI be in the trailer?

The PSI in the trailer should be about 14.7 pounds per square inch. If I remember from my high school science class correctly.

Yes they are original equipment tires. I have had them on for 4 years now, and I don't remember how I heard that 90 PSI was the proper inflation for the tires. I recently got a TPMS and the guy said he would recommend 110 PSI for the G rated tires. Thus I inquired what people were doing.

rbp111 wrote:
I have a trailer which has Sailun G rated tires. The maximum PSI of air is listed as 110 PSI. I was carrying 90 PSI but recently was told that the maximum PSI, that is 110 PSI is the amount of air I need to carry.
Which is the amount I should have in the tires?

Are they the Original Equipment tires?


For original equipment tires the correct inflation pressure is displayed on the tire placard.


If they are replacement tires with the same designated size but a higher load range you can inflate them to the same PSI as the OEM tires or increase the PSI to a value not to exceed the wheel rating or maximum sidewall pressure on the tire.


If they are a 'plus sized" tire, the tire industry standard is to insure they provide, at the minimum, a load capacity equal to or greater than the the OE tires provided.


There is no provision in the standards to inflate tires to the load carried. That's an off-shoot of the FMCSA regulations and not applicable to FMVSS standards.

The GY ENDURANCE tire has been on the Market now for a full two years.

ZERO issues that I have heard of. One person admitted his problem was road hazard on another forum.

Anyone heard of a legitimate ENDURANCE failure?

I bought a set two Summers ago for my heavy boat/tandem axle trailer. I tow with it all Summer 70-75mph and in and out of Salt Water constantly.

fj12ryder wrote:
"We'll get more reserve load capacity and even lesser risk of a failure."

More load capacity only means something if the tires are worth a hoot. I had a ton of load capacity with the "E" rated ST tires that came on my 5th wheel. I have a max of 2,500 lbs. on a couple of wheels, and those ST tires were rated for 3,400 lbs. Plenty of load capacity, but two of them destroyed themselves. So you can inflate to your heart's content, but if the tires aren't reliable it means exactly squat.

I have heard that the Endurance tires are developing a decent reputation.

You raise a good point that the tires must be decent to start with, nevertheless reserve capacity is still a factor.

Cummins12V98

Yes. Per RV manufacture spec and tire rating as well as what is recommended on the tire. On my truck I also use tire ratiing and not what is on the Ford sticker. The rating on the Ford door sticker will give a softer ride for the truck, but Ford does not make the tires. I would recommend using the rating used by the manufacturer.

"We'll get more reserve load capacity and even lesser risk of a failure."

More load capacity only means something if the tires are worth a hoot. I had a ton of load capacity with the "E" rated ST tires that came on my 5th wheel. I have a max of 2,500 lbs. on a couple of wheels, and those ST tires were rated for 3,400 lbs. Plenty of load capacity, but two of them destroyed themselves. So you can inflate to your heart's content, but if the tires aren't reliable it means exactly squat.

I have heard that the Endurance tires are developing a decent reputation.

The advantage to running ST tires at max. sidewall psi is that you get the highest possible reserve load capacity for your particular tires and trailer weight. You want at least 15% reserve capacity and more is better to reduce the risk of a tire failure. I'd weigh the trailer fully loaded to max. and compare to the total load rating of the tires. If it doesn't hurt the tires to run at max psi, why not?

Roger Marble talks about it on his RVtiresafety.net blog. We upgraded from the OEM LRC tires to LRD Marathons (made in
China) and have about 30% reserve load capacity and 20+K miles later, no tire issues. I always keep the tires inflated to 65 psi. We're going to replace them with the new Endurance tires in same width and run them at their 80 psi rating. We'll get more reserve load capacity and even lesser risk of a failure.

"I eventually figured out I need to buy quality tires to replace my OEM junk, but it did not happen overnight."

I ordered my 15 RAM, I knew it would be coming with POS NEXXEN tires. So a month before my truck came in I went to Discount Tire and ordered 6 Michelins. At 200 miles i had them installed and sold the NEXXEN the first call for $650.

I will be honest i only made 40k on that set of michelins but they credited me $600 towards ANY tire I wanted to buy. I chose the new and "IMPROVED" Michelins. So far at 24k they are wearing MUCH better than the last set.

wilber1 wrote:
Load inflation charts give load limits for different pressures, they are not recommended pressures.

Who said they were??? Even the tire inflations chart where it says MAX is NOT recommended.

Inflation charts are there to assist you in running the tires at their best performance. Meaning BEST possible stopping, BEST possible ride and BEST possible tread wear.

Tires are part of your suspension, they should be aired to provide the best possible ride and stay within the tires capability.

98 RAM 120K Michelins, 100k BFG's. 86 C20 120k Michelins and 80k on Generals. The list goes on and on. All it takes is QUALITY tires ran at the proper pressures for the load along with a GOOD alignment.

Tires have a built in factor just like anything else does.