Community Forums

JWLSC · 05-10-2016, 01:37 PM

I have not had my coach long and have not had it weighted. Can any Eagle coach owners tell me what tire pressure you are using. I believe I have Michelin XZA3 EVERTREAD 275/80R22.5, will verify later today.

Gary RVRoamer · 05-10-2016, 02:51 PM

Doesn't your coach have a placard on the wall by the driver seat giving recommended tire pressures as well GVWR and such? Use that until you can get it to a scale. It should be good for the max allowable axle load. Or call American Coach and get the axle load ratings, then inflate the tires for that max axle load.

If you don't have that info, I would use the max load pressure on the tire sidewall. Probably excessive, but it's safe.

Using somebody else's tire pressure is risky, even among the same brand. Coaches come in different lengths and weights, and the axle get loaded differently with different floor plans and different owners gear. Too little tire pressure and you could have serious problems, e.g. poor handling, blow-outs, tire wear, etc.

GlennLever · 05-10-2016, 02:58 PM

Mr_D · 05-10-2016, 03:01 PM

Problem with just weighing the axle is that one side can be much heavier than the other. The heavier side can be 1# to over 1,000#'s heavier, thereby leaving that side underinflated. That's why all corner weighing is so important!

mackwrench · 05-10-2016, 04:42 PM

My 1999 Eagle list 105 ft and 115 for rear. (Mine are 295/75R22.5 G399 goodyears, I run all 6 at 115)

As posted, you should weigh the coach. Most truck stops have a scale, but only for total and/or axle weights. While the weight of each wheel end is what a perfect world wants, axle weights will do just fine.

Something else that must be considered that's not often discussed is road speed at max load. Best practices call for up to 10 psi over spec for extended high speed. If you plan on long interstate road trips (I do) pump them up.
As far as axle weight to psi, the link below has a table on page 90 that shows your tire size, max load and pressure /speed, it's a lot of info.....

http://www.michelintruck.com/assets/...k_Sept2011.pdf

Note as well the next time you pull up to a FedEx, UPS or Walmart type fleet truck, most will have a decal over the tire area with tire psi, and most are 110 psi and they haul 80k using the same individual rear axle weight rating as your coach.....your coach has a heavier rated steer axle, but your load range H tires make up for that.

Best advice is what ever psi you use, make sure they have that in them every trip.

FormerBoater · 05-11-2016, 06:01 AM

The best I can do for you John is give you the weights of my Eagle which is the identical model. I am assuming that you have a Spartan Chassis. If not, please ignore the information that I am posting.

Please ignore Glenn's post as that info is for a Gillig chassis unless you have a Gillig.

Here are the axle weights for my 1998 American Eagle 40 EVS with full fuel, full fresh water, full propane, empty grey and black tanks with no folks aboard:

Front: 10,700 pounds

Rear: 18,080 pounds

You need to add the weight of your passengers to the front axle and set the air pressure accordingly per the Michelin charts for your tire size. Most add 5 lbs of air as a safety measure.

You can run at the placard air pressures as stated by Gary, however it may not be optimum for the best ride in your Eagle.

Gary RVRoamer · 05-11-2016, 11:29 AM

Quote:

however it may not be optimum for the best ride in your Eagle.

Right, but getting to "optimum" is the reason for weighing wheel by wheel. If you don't do that, you cannot be "optimum".

There are various algorithms for estimating max axle end weights when you only have total axle load to work with. It's simple enough to make an allowance for unbalanced loads, but there are different views on how much of an allowance to make. Since I was suggesting he run at the pressures given for max axle load anyway, I did not mention it in my previous post.