Question on wheel psi rating

ekirkland wrote:
It appears that in the three weeks since this thread, Sendel has increased the max pressure on the T09 wheels on their website from 60 to 80 psi. Strange that the girl I exchanged emails with a few weeks ago didn't mention that; I guess she just repeated the old website numbers. I don't know if they are now building to higher specs or re-vamped their rating scheme. I left an email asking about it.

No company is going to advise exceeding whatever official rating they have on a product. An employee who did that would probably be fired. So IMO it was silly to even ask them.

Also IMO, all the jabber about wheel pressure rating is silly too. Tires are rated for a load X at pressure X. Wheels are rated for a load, and the pressure rating simply compliments the tires available in the same load rating. Ever notice the load rating on wheels corresponds with tires? Ever notice tire ratings are consistent between all manufacturers? All good stuff, and setup to make it easy for all of us to match things up.

The reality is that the difference between 65psi and 80psi is not going to blow up a wheel, in the RV world. But don't exceed the load rating. Upgrade to D or E, run the higher pressure, but don't ever exceed the original load rating, and enjoy the added safety margin. The stronger carcass of the higher rated tire will provide better resistance to bruising and belt damage.

It appears that in the three weeks since this thread, Sendel has increased the max pressure on the T09 wheels on their website from 60 to 80 psi. Strange that the girl I exchanged emails with a few weeks ago didn't mention that; I guess she just repeated the old website numbers. I don't know if they are now building to higher specs or re-vamped their rating scheme. I left an email asking about it.

I did email Sendel and they said not to exceed the 60psi max for the wheel. So, if I run D-load tires the should be at 60psi instead of the 65 max for the tire. So, if I need to get upgraded wheels to go with my tires, I'll go ahead and move up to 15". I'm just having a hard time convincing myself to fork out another $400+ for new wheels in addition to new tires.

Jayco apparently supplied the bare minimum tire/rim combination. Check with Sendel on running D or E rated tires and added PSI.

If possible, up-grade to 16" rims, E rated tires, and no worries.

Why not contact the manufacturer, Sendel and see what they say. Their website doesn't seem to have any tech. info.

After reading this recent blog article on wheel failure, I wonder if higher lateral forces could result from the load range D tires and potentially lead to wheel failure?? Maybe psi isn't so much the concern? Not a tire expert, just curious...

ekirkland wrote:
So, are you saying you would not hesitate to inflate load range D tires to 65psi on 60psi wheels?

If you do not have a choice, yes.

The alternative is to run your tires underinflated and we know what that does.

Plus, the best situation is to do an upgrade, so the situation doesn't exist!

“Never exceed the maximum load capacity and/or inflation pressure of the wheel.”

That is a quote from the Bridgestone/Firestone replacement tire selection manual.

Note: Specifications for rims/wheels are a product of the Society of Automotive Engineers (SAE).

I can't imagine 5 psi will make any difference. By the way, the tire the OP asked about is NOT a ST tire and it has a Q speed rating. Q = 99 mph.

I'd suggest finding out what the load carrying capacity of those tires are at the maximum wheel pressure.

Multiply each tire's capacity @ 60psi by the number of tires you have.
Let's say the max load at 60 is 2000 and you have 4 tires.
Max=8000

Run your trailer with a normal load over to the scales.
Let's say your trailer weighs 6500 lbs.

Does the overall capacity exceed the load? If not, you are fine in that respect.

Next weigh each side, or each wheel position. Does the capacity of each tire @Max wheel pressure exceed the load? If so for all positions, then you are fine.

I wouldn't exceed pressure ratings or capacities if your load is within the capacity at rated pressures/load ranges.

If your load is greater than than the capacity at that pressure, make the determination if you are willing to accept that. If you are 100 lbs or a 1000 over, only you can decide whether that's ok or not. 100 over may be ok, 1000 is not (in my book). If the load is over, look at other options.

Michelin publishes loads for specific pressures for each load range. This guide generally applies to all brands of tires of the same size and load ratings.

I always ran right at or slightly over capacity on the rear on our old motorhome, as it simply didn't have much capacity over the empty weight. We never loaded very heavy anyway, so I accepted that fact.

I put 15" load range D LT tires on our fifth wheel; I don't recall the exact numbers but it seemed they had about 1500 lbs more capacity than the loaded trailer weight.

Hope that helps.

Most wheels have the PSI rating stamped on the backside. I would get higher rated wheels to match the new tires rather than risk a wheel failure. If the cost of new wheels and tires was too much and I still wanted new tires I would not exceed the PSI rating.