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CWtheMan · 02-10-2021, 09:32 PM

All of a sudden RV trailer tire inflation pressures are popping-up again in a number of forums I follow. The misconceptions are always very common. I’m just going to post “how it’s supposed to be done”

First is the perception that RV trailer tires can be inflated to the load carried. I know where that misconception comes from and I’m not going to confuse this post with another agencies standards. Those that are convinced that method is common with FMVSS fitted tires need to know the vehicle must go to the scales and get individual wheel/tire position weights. The standard by that agency requires all tires on the same axle to be inflated to support the heavies loaded tire position. Don’t forget, on your next trip to get new weights.

Our RV trailers and automotive tires are all inflated to the same standard in the FMVSS. That standard is supported by the USTMA and all of their participating members. Plainly put; the correct inflation pressures for your OE tires are the vehicle manufacturer’s recommended cold inflation pressure. Anything from what has been recommended to tire sidewall max is optional. Inflation pressures for plus sized tires start at the vehicle certification label. A new recommended inflation pressure must be established using a load inflation chart that provides an inflation pressure that will provide the load capacity the OE tires provided.

Load inflation charts are not recommendations. They are standardized and primarily used by tire installers to insure a correct vehicle manufacturer’s recommended cold inflation pressure supports the loads on the certified GAWRs they are fitted to.

The inflation pressure shown on a tire’s sidewall is there to inform users of the PSI value needed to gain full load capacity – also shown on the tire sidewall – from that tire.

02-10-2021, 09:32 PM	#120
CWtheMan Senior Member Join Date: Feb 2010 Location: Taylors, SC Posts: 3,031	RV trailer tire inflation pressures All of a sudden RV trailer tire inflation pressures are popping-up again in a number of forums I follow. The misconceptions are always very common. I’m just going to post “how it’s supposed to be done” First is the perception that RV trailer tires can be inflated to the load carried. I know where that misconception comes from and I’m not going to confuse this post with another agencies standards. Those that are convinced that method is common with FMVSS fitted tires need to know the vehicle must go to the scales and get individual wheel/tire position weights. The standard by that agency requires all tires on the same axle to be inflated to support the heavies loaded tire position. Don’t forget, on your next trip to get new weights. Our RV trailers and automotive tires are all inflated to the same standard in the FMVSS. That standard is supported by the USTMA and all of their participating members. Plainly put; the correct inflation pressures for your OE tires are the vehicle manufacturer’s recommended cold inflation pressure. Anything from what has been recommended to tire sidewall max is optional. Inflation pressures for plus sized tires start at the vehicle certification label. A new recommended inflation pressure must be established using a load inflation chart that provides an inflation pressure that will provide the load capacity the OE tires provided. Load inflation charts are not recommendations. They are standardized and primarily used by tire installers to insure a correct vehicle manufacturer’s recommended cold inflation pressure supports the loads on the certified GAWRs they are fitted to. The inflation pressure shown on a tire’s sidewall is there to inform users of the PSI value needed to gain full load capacity – also shown on the tire sidewall – from that tire.