RV Tire pressure

[WMass camper]

The tire and loading chart on the MHC RV, states “the weight load of cargo is not to exceed 2900 pounds at a tire pressure of 95 psi”. We have new Sailun tires ST235/80R16 load index 129, the weight rating on the tire has a maximum load of 4080 pounds at 110 psi. If I do not exceed 2900 lbs of cargo weight, can I inflate the tires to only 95 psi per the RV placard or do I inflate the tires to the psi rating on the Sailun tire at 110 psi?

 

[mlh]

This question comes up often. The higher the tire pressure the more weight it can carry and the cooler it will run. So there is not much reason not to run your tires at anything but near max pressure which for your tires is 110 pound. The exception to that will be if you have 80 pound rims. Your rims max pressure should be stamped on the inside of the wheel on one of the spokes.
Lynwood

 

[richfaa]

We have always been told at the seminars at the fall rally to inflate the tires to the stated specs on the tire.

 

[DQDick]

We have always inflated our tires to within a couple of pounds of the recommended max.

 

[FastEagle]

The tire and loading chart on the MHC RV, states “the weight load of cargo is not to exceed 2900 pounds at a tire pressure of 95 psi”. We have new Sailun tires ST235/80R16 load index 129, the weight rating on the tire has a maximum load of 4080 pounds at 110 psi. If I do not exceed 2900 lbs of cargo weight, can I inflate the tires to only 95 psi per the RV placard or do I inflate the tires to the psi rating on the Sailun tire at 110 psi?

The answer to you inflation question is found in your decision to use replacement tires with load capacity reserves that exceed the vehicle manufacturer's recommendation.

The correct inflation pressure for your old tires was 95 PSI. That, combined with a load inflation chart for tire size designation ST235/80R16 LRF provides a tire load capacity the vehicle manufacturer has deemed appropriate for your OE tires. By adding a tire with a higher load range letter (G) you have the option to increase your tire's load capacity reserves with increased inflation pressures all the way to 110 PSI which is the inflation pressure needed for the replacement tires to provide their maximum load capacity.

If you measure the load strength of your tires you will find that at 95 PSI both LRF & LRG provide an identical load capacity.

Although you may have added some extra tire durability by selecting the all steel cased LRG tires, it's not measurable. The only way to get extra load capacity protection is with increased inflation beyond 95 PSI.

The only load indicator used by the vehicle manufacturer in selection your OE tire size is the value of the trailer's certified GAWRs. It's a minimum governing body requirement.

 

[Dave W-FRF]

Do you actually have wheels that are rated for 110psig? A 330RL has usually had, at least in the not too distant past, 6 lug Sendel TO3 wheels with a 6K axle. Those wheels are rated at 94psig max with a normal operating inflation pressure of 80psig. If indeed you do have 110psig rated wheels, then no problem .

 

[FastEagle]

Do you actually have wheels that are rated for 110psig? A 330RL has usually had, at least in the not too distant past, 6 lug Sendel TO3 wheels with a 6K axle. Those wheels are rated at 94psig max with a normal operating inflation pressure of 80psig. If indeed you do have 110psig rated wheels, then no problem .

The vehicle manufacturer can not provide OE wheels that can't provide the max load capacity for the OE tires fitted to them. Therefore, the ST235/80R16 LRF tires and T03 wheels would be a mismatch.

At 110 PSI those LRG tires will feel like bricks when rolling along at 65 MPH on the OPs trailer. Reasonable load capacity reserves is good insurance. However, IMO, tires with a maximum load capacity of 4080# ea. are way overkill for 6000# axles.

 

[AZ Traveler]

Do you actually have wheels that are rated for 110psig? A 330RL has usually had, at least in the not too distant past, 6 lug Sendel TO3 wheels with a 6K axle. Those wheels are rated at 94psig max with a normal operating inflation pressure of 80psig. If indeed you do have 110psig rated wheels, then no problem .

Dave,

All the newer Montanas and HC have 110 PSI wheels.

 

[Dave W-FRF]

The vehicle manufacturer can not provide OE wheels that can't provide the max load capacity for the OE tires fitted to them. Therefore, the ST235/80R16 LRF tires and T03 wheels would be a mismatch.

At 110 PSI those LRG tires will feel like bricks when rolling along at 65 MPH on the OPs trailer. Reasonable load capacity reserves is good insurance. However, IMO, tires with a maximum load capacity of 4080# ea. are way overkill for 6000# axles.

I posed a question with some info to the OP since he did not include enough info. Your response icondescending to me - again!

 

[Dave W-FRF]

Dave,

All the newer Montanas and HC have 110 PSI wheels.

I hope so but even the new, 2021 Keystone spec sheet states that a 330RL has 6K axles that normally take 6 lug wheels which are usually 80 psigrated. And the reason for my question to the OP

 

[FastEagle]

I posed a question with some info to the OP since he did not include enough info. Your response icondescending to me - again!

That's one of the major problems with two dimensional communications.

I had reviewed the OPs trailer specs. According to them the OE tires were ST235/80R16 LRF, max load, 3750#. SenDel 16x6 wheels have a max load of 3580#.

 

[Carl n Susan]

...I had reviewed the OPs trailer specs. According to them the OE tires were ST235/80R16 LRF, max load, 3750#. SenDel 16x6 wheels have a max load of 3580#...

The OP never said what tires or rims were installed. Speculation of Load Range "F" tires and T03 have not been verified. Maybe we can wait for the OP to respond before condemning tire/rim choice?

 

[bobbecky]

It looks like the 6,000 axles used on the High Country, 2020 and 2021, maybe earlier too, are coming with 8 lug drums for the 8 lug wheels. https://www.trekwood.com/products/1390816/Axle-6000-Straight-D60-8-Lug-TM-12-E-Self-Adjust
So, It is likely that the same wheels used on the Montana line are also used on the High Country line.

 

[FastEagle]

The OP never said what tires or rims were installed. Speculation of Load Range "F" tires and T03 have not been verified. Maybe we can wait for the OP to respond before condemning tire/rim choice?

In post #1 the OP said his trailer's tire placard recommendation was for 95 PSI. That coincides with the specs for that trailer having LRF tires.

The part about T03 wheels was because someone else suggested that they may be the OEM wheel size. I was just pointing out that that particular wheel could not have been used as OEM because it doesn't have the load capacity to support the load capacity of a LRF tire.