understanding Michelin recommendations

[derh20]

I realize I am not the sharpest tack in the box, but i am having trouble understanding the chart. I have a 29' with 3 slides and have LT225/75R16 tires. My weight is 3900 lbs in the front and 9700 in the rear. I am about 200 lbs over on the rear and light in the front. Looking at the chart, for 80 lbs, I read it to have a max of 2680 lbs for singles and 4940 lbs for dually's. Both of these readings are far lower than I have. How am I reading this wrong?

[ronfisherman]

Closed thread.
Refer to other thread on subject.
Michelin Tire Pressure

[AH64ID]

Mich F wrote:


To put into numbers, what others have stated, that 2,680# for a single is per side, so the front tires with 80# psi is 5,360# per axle. The rear axle 4,940# for duals is also per side, which means 9,880# per axle.
Are those numbers from when fully loaded with fuel, passengers and gear/supplies?

Precisely.

You are very close to tire limits on the rear. I would look at your storage and see what heavy items you can move from behind the axle to between the axle. Everything loaded behind the rear axle will remove weight from the front axle which adds more than the weight of the item to the rear axle. Every pound will make a difference.

If you are unable to shift much weight you might see if 235/85R16 or 245/75R17 tires will fit when the time comes, both sizes will carry more weight at 80 psi.

Dennis M M wrote:


So you are good. You should be good at 60 PSI all the way around.

How did you come up with that number? The rear axle is within 100lbs per corner of the load limit, 60psi is nowhere near enough for the rear axle.

Per the Michelin chart 60 psi would give the OP 7980lbs of load rating for the rear axle, well under the 9700lbs he scales at.

[Mich_F]

derh20 wrote:
I realize I am not the sharpest tack in the box, but i am having trouble understanding the chart. I have a 29' with 3 slides and have LT225/75R16 tires. My weight is 3900 lbs in the front and 9700 in the rear. I am about 200 lbs over on the rear and light in the front. Looking at the chart, for 80 lbs, I read it to have a max of 2680 lbs for singles and 4940 lbs for dually's. Both of these readings are far lower than I have. How am I reading this wrong?

To put into numbers, what others have stated, that 2,680# for a single is per side, so the front tires with 80# psi is 5,360# per axle. The rear axle 4,940# for duals is also per side, which means 9,880# per axle.
Are those numbers from when fully loaded with fuel, passengers and gear/supplies?

[Dennis_M_M]

Michelin charts can be confusing. The one for RV Aplications includes this statement:

"For RV use only, Michelin displays tire loads per axle end in the load and inflation tables, as we recommend weighing each axle end separately and using the heaviest end weight to determine the axle's cold inflation tire pressure. For control of your RV, it is critical the tire pressures be the same across an axle, while NEVER exceeding the maximum air pressure limit stamped on the wheels."

So you are good. You should be good at 60 PSI all the way around.

[enblethen]

Odd chart on their website.
4940 is for both tires on the rear. 2470 pounds per tire. at 80 psi
2680 for front at 80 psi
They must be concerned with side wall issues.