Tire pressure specs - discrepancy between Fleetwood and Michelin

[rguild]

I have a 2015 Fleetwood Bounder 33C which I purchased last January. I am a full timer and already have 15,519 miles on it. I am concerned because I see tire wear on the outside of the tread and the pressure specs on my Michelin are 110 PSI while the specs stipulated by Fleetwood customer service are 90 PSI.

As we know, under-inflation leads to the uneven tread wear on the outer sides. I had the opportunity to discuss this with a Goodyear shop manager who confided with me that the same situation occurred with the infamous Ford Explorer rollovers in the last decade. He said Ford's PSI specs were well below the specs recommended by Firestone whose tires Ford put on the Explorers.

He recommended I split the difference between 90 PSI and 110 PSI but cautioned it could cause problems with my insurer in the event of an accident.

I have contacted Fleetwood customer support about this and have been told I needed an alignment but the tire guy told be the problem was not alignment but under inflation.

Can someone offer advice? At the rate I am getting outer tire wear, I will need replacements well before the expected tire life. I suspect I will also have avoided the tire warranty.

[mackwrench]

This is no doubt the most "discussed" topic on the forum here...But since your asking, I run 110 in all 6 tires. But mine are 22.5

But they'll be many here that will disagree, that you'll have to weigh the coach by each wheel....Have you look at some chart/graph to explain it away

Why make it harder, understand that under inflatation leads to tire wear AND heat. A under inflated tire will blow out....That's the 2nd most discussed topic here


The company that built the tire may not know what I'm using it for, but they Know how much air to put in it.

Enjoy your coach!

[1killowatt]

Good Year had a problem with the tires wearing the treads near the sidewall. They called it feathering. You can get your new tires thru FMCA (Michelin) tire program (fleet prices).
When you have tires balanced, be sure to get the Road Force Balance.

[1killowatt]

The michelin 19.5" tires recommend 95 psi

[Crasher]

When you say outer wear do you mean the outer and inner edge of the tire is wearing. If so, then underinflation is the cause of the wear. If just the outer edge and not the inner edge is worn, then it is an alignment issue, most likely too much toe in. Who do you think has more knowledge regarding the proper pressure for a tire, the tire maker or Fleetwood?????

[Sweetbriar]

Without knowing the axle weights of the coach the correct pressure is a SWAG, Scientific Wild A$$ Guess. Fleetwood's numbers are normally based on the needed pressure to carry the maximum axle weight for the recommended tire size and load rating. Michelin's numbers will probably be the maximum pressure for the maximum load the tire can carry. Your Bounder probably has a greater load capacity with the tires than the axles so the advice to split the difference would be a WAG, Wild A$$ Guess.

Rapid outside edge wear is normally a sign of an alignment problem. In particular excessive camber which may or may not be adjustable. Under inflation will normally wear both edges of the tire.

Coach builders normally do a quick alignment check as the last step coming off the production line. Problem is the coach is empty of the owner stuff. Loading can cause problems. Rotate your tires and call Ford to see if they will pick up the tab for an alignment check as a warranty item.

I used a lot of maybe's, probably's and normally's so my whole post might just be a DA-WAG.

[mrfix]

I had the same issue, alignment corrected the issue, toe in was extreme .75" the spec is 0 - 1/16" toe in.

[Sue46]

When we bought our MH the manual said after it was fully loaded get a front end alignment. After that we got an axle weight as soon as we could, set out tire pressures based on the Michelin charts. A few months later we were able to get a 4 corner weight and reset out pressure.

I would not trust Fleetwood numbers, they are very general and have no idea how much you really weight. Tire mfgs. would not provide pressure charts if they did not consider the weight vs. the pressure important.

[computerguy]

Wow, I must be getting old and grumpy. Maybe I need time away from these forums and all the misinformation.
The Bounder comes with 22.5 rims and Michelin tires. Commenting on 19.5 rims or Goodyear tires is not related to this thread. It just confuses things and people asking for help.
The Michelin tires have the MAX tire pressure on the sidewall. It is not a recommended tire pressure. If you want to over-inflate your tires and probably have the most unpleasant ride you can go ahead and fill it to the max otherwise see the tire inflation charts.
Fleetwood used those charts to indicate the tire pressure on the Federal Certification plate that is required on all vehicles.
See here for the recommendation based on the load of your RV and the tire you have:
Michelin RV Tire Pressure Charts

To the OP, have you weighed your coach at each wheel? Is the uneven wear even on each front tire?
Weight will do strange things to tires and why I ask those questions.
If you are within weight limits (GVWR and GAWR) and evenly distributed then an alignment should be done before anything else.

[mackwrench]

...

[BigBadDad]

Get a certified scale weight on all four corners and inflate accordingly.

[Mageksl]

All the comments on weight and adjusting tire pressure to match are right on.

You should always go with manufacturer recommendations. Michelin makes tires, Fleetwood makes coaches.

[4x4van]

Originally Posted by rguild

the pressure specs on my Michelin are 110 PSI while the specs stipulated by Fleetwood customer service are 90 PSI.

That is an incorrect statement. The number on the tire sidewall (110psi) is the pressure required for the maximum weight that the tire can carry, regardless of what vehicle the tire is installed on. The number stipulated by Fleetwood on the placard (90psi) is the pressure required for YOUR RV at IT'S maximum weight. Your coach has a front GAWR of 8,000# and a rear GAWR of 15,000#, both of which correspond to 90psi per Michelin's inflation/load table. Again, that 90psi is for those tires, installed on your RV, loaded to it's maximum weight; if you weigh less, then you may be able to safely run even lower pressures.

At 110psi (what you are reading on the sidewall), your tires will support 9,350# front and 17,640# rear; way over what your RV should ever weigh fully loaded.

[Smitty77]

For any coach:

1) Get coach loaded for travel, obtain four corner weights
2) Consult the tire manufactures weight to PSI charts. Add on the amount you feel comfortable having as contingency. (I use 10%, and young up to the next 0 or 5 digit, to keep it easy. Say recommended PSI is 97, I'd add 9.7 to 104.7, then round up to 105 PSI for that axles tires.)
3) Full all wheel alignment.
4) If vibrations are evident, back to have the tires balanced, and or add beads or Centramatics (I run with Centramatic's on all axles.)

OP - Best of luck to you, and any coach with any tire, this would be my recommendations.

Smitty