[Charles]

While everyone has their guages out can I get a double check? My bus weighed out as follows:

Left Side Right Side

Front — 8,036 7,725

Drive — 8,761 9,332

Tag — 5,962 6,325

Using Michelin as the guide is 120 front, 75 drive and 90 tag correct without any added cushion ?

[Archived]

George, My interpretation, using the highest weight per axle side would be 120, 85, 85

The assumption is 315 XZA on all positions. Michelin lists 85 as the lowest and I am guessing that is over inflating the drive but the absence of lower pressures on the chart seems to indicate they do want to see that pressure. It could also mean they don’t think anyone will use a 315 on an axle with a lower weight.

I doubled the highest weight per side to get the pressures.

[Archived]

Thanks for th input.

[Richard]

Isn’t there a chart for pressure v. weight on Michelin’s web site in the RV section?

[Archived]

Yes they have a number of charts for different size tires. Unfortunatly the 315/80/22.5 chart does not show sufficient weight. Called Michelin for info, will call me back in a day or two.

[Larry & Diane]

Arn’t the weights shown per wheel/dual wheel not per axle? i.e double the weight for the entire axle to give the correct pressure. As an example, your steer pressures should be 100-105lbs?

[Corey]

The chart shows the axle weight which assumes the side to side balance is good and it differentiates between a single tire per side or dual tires as in the case of the drive wheels.

If the axle weight is below the lowest weight listed on the chart you will never go wrong using the lowest pressure listed. I suppose you could extrapolate but I would be reluctant to do so without some indication from Michelin that is OK.

https://http://www.prevostcar.com/tire-pressure-calculator

[Larry & Diane]

I didn’t want to start a new thread so I thought that I would post here.

What is the max difference that you would tolerate between the duals?

For instance, I’m noticing about 3 to 4 lbs. difference between the passenger side duals and about 3 lbs. on the driver side.

At what point would you want to match them up? Should I do it now?

Thanks,

Mark

[Bernie]

You can run on a deflated duel at 25 mph and limp in to a tire repair if you do not have an air hose or one that is long enough. I once limped in over 45 miles without causing any damage to the rig. 10# is not a problem just go slow.

Michael xxxxxx (retired tour bus operator)

This post from a very popular RV web site. Advice given to another member when he discovered a flat less then 10 lbs pressure on his inner dual. Had no hose to fill tire and reported he had just replaced all tires with new Michelins.

He was asking members what he should do ? Was he able to drive with tire nearly out of air ?

Michael’s last name has been deleted

[AL]

Don’t fret MM, the side in the sun will be 3-5lbs higher.

Unless you did the checking at night.

Later

bv

[Archived]

I had a similar occurance on an insied dual, got home and found the inside drive pressure at 0 so not only did I replace that tire but replaced the outter drive because with the inside flat I over rated the outside.

It looked fine but I knew I stressed it becaus of the weight that one tire was subjected to.

[Corey]

MM, They should be the same. But as long as they are at the pressure recommended by Michelin or higher that can be adjusted at your convenience.

I don’t think anyone should ever “limp” on a bad tire. Not ever. Not unless they treat that tire as junk if it gets them where they need to be, and replace it.

[Dan]

I’m running higher pressures than what is recommended in all the tires. I feel that it gives me a cushion and it’s way lower than the max cold pressure listed on the tire.

I’m reading all the info from the built-in pressure monitoring system.

All the tire temps run about the same until the end of the day when it’s hot and 300+ miles under my belt. The rears seem a little hotter with the inner duals running a few degress warmer as they are next to the engine and transmission. I’m talking about 144 for fronts, drive (outer) and about 150 (inner) and 144 for tags (at the end of the day and near 90 degree ambient temp).

Mark

[Corey]

MM,

There’s nothing wrong with the temps your getting. Your looking for consistency.

Your default temp warning setting is probably set between 176 to 195 degress, read your book or ask Liberty.

Mine is set to 185 degrees F.

Later

bv

[Tom]

MM, Bernie has it right. If the tire pressures are consistent with the Michelin tire pressure calculations the tire temps are going to be quite close to one another.

What you are looking for is a change in what is a pattern. Actually that is what holds true for all value measurements because whether it is your tire pressures, coolant temp or oil pressure you get a sense of “normal” and almost always a change from what you are used to seeing is your first indication something needs attention.