Tire air pressure

[Michaelschmidt]

I have a 2018 Thor 24hl motorhome and woundering how much air pressure is what other people with the same coach run in their tires

 

[FloridaSon]

Have you weighed it loaded like you camp?

 

[Rich W.]

As mentioned above, weigh it loaded, and consult the load chart for your tires. Your load could be different from others with the same unit and of course others with the same unit might not be using the correct pressure.

 

[Sonic]

Use the Thor recommended tire pressure on the label near your drivers seat (that PSI assumes you’re carrying the maximum weight) until you get the coach weighed, then adjust accordingly as mentioned in the above posts

 

[Michaelschmidt]

I was looking for someone to let me know what they run in their tires, just as a “to get started” because someone one out there must have a Thor 24hHL Sprinter that they have been driving and can tell me what air pressure they use. I don’t think everyone that has a motor home takes it and gets it weighed

 

[Rich W.]

You can use the manufacture’s recommendation, the max cold rating on the tires or get it weighed. The reason to weigh it is to get the tire pressure correct to the nearest 5lbs for your load. As an example, after weighing and consulting the chart, I put my rears are at 95 and my fronts are at 105. My sticker lists 120 for the rears and 130 for the fronts.

The max is 130 cold but that would produce a less comfortable ride and probably wear the centers out. Too little would of course cause excessive heat build-up, outer edge wear, and a high probability of failure. So it makes sense to get it right, but if you just want a ballpark idea, the sticker on the coach will get you there.

If I used the manufacturer’s recommendation I would have an unnecessarily harsh ride. You’re right that most people probably don’t weigh their coaches, but the ones who want to get it right do. And we don’t just weight the coach, we weigh each corner individually and use the highest end weight for each axle. That may sound excessive, but its worth it to get it right. It’s probably less important for smaller rigs, but tires are expensive, failures can be catastrophic, and these things ride harsh enough without making it unnecessarily worse.

 

["EZ"]

It's hard to give someone good advice that doesn't want to hear it.

 

[Michaelschmidt]

Thanks, your right- the door label on the Mercedes sprinter truck says 61 lbs, but that would seem that was determined by Mercedes without a motor home built on it. I just was hoping some one could comment and say, I run mine at say 65 pounds or something like that instead of going to a scale.

 

[Rich W.]

That would be nice, but that someone could be doing it wrong too. But its also probably less critical on a Sprinter chassis. My rear axle is carrying over 21,000lbs, front around 11,100. So its more an issue for me. FWIW, my neighbor has one and he runs 61 psi on all six. But his doesn't have slides so it weighs less.

 

[Bob K4TAX]

Most tire failures are caused by (a) road hazards, (b) low tire pressure causing sidewall flex and overheating.

As to weighing the unit loaded, I find that from site to site and week to week our contents change, thus the load changes. Thus weighing the RV, I view, is not a practical situation.

If the tires are of the original type and size, I use the manufactures ratings found on the appropriate placard. Otherwise, inflate to the maximum cold pressure as found on the sidewall of the tires.

Bob