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Fred Christy · 07-18-2013, 07:41 PM

I was running 110 in the rear and 105 in the front. Yes I have wheel outside and steel inside.

Fred Christy · 07-20-2013, 09:59 AM

This is the clearance I have on the 315's

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distaff · 07-22-2013, 05:12 PM

Fred - I'm surprised at your pressures. I expected your fronts to be harder than your drive tires.

What are you getting for axle weights?

Fred Christy · 07-23-2013, 07:54 PM

Quote:

Originally Posted by distaff

Fred - I'm surprised at your pressures. I expected your fronts to be harder than your drive tires.

What are you getting for axle weights?

I am not for sure now. Every time we go on a trip my wife loads more stuff in the Motorhome.
I got tired of weighting it.
I have almost 8000 miles on these tires and they are wearing fine, riding smooth with 100 psi in the front and 105 in the rears. NO Issues at all. When these wear out I will replace them with the same.

kketterling · 07-24-2013, 09:12 AM

Fred: When I look at your photo it looks like the Michelins have little or no bulge on the side wall. On my Badyears the bulge at the bottom is very pronounced. Is it just the picture or is your spacing at the bottom of the dual about the same as at the top?

Thanks

Fred Christy · 07-24-2013, 09:37 AM

Quote:

Originally Posted by kketterling

Fred: When I look at your photo it looks like the Michelins have little or no bulge on the side wall. On my Badyears the bulge at the bottom is very pronounced. Is it just the picture or is your spacing at the bottom of the dual about the same as at the top?

Thanks

There is more room away from the bottom. The Michelins do have a radial bulge at the bottom. That was the only area I was concerned about the tires kissing. But they didn't so I lowered the air pressure down to what you see now.

kketterling · 07-24-2013, 09:44 AM

Thanks. I found a tire dealer that will let me test a set of 315s on the rear so think I'm going to go that route. Just have to pay for extra mounting cost if it's a no go.

terry735001 · 07-24-2013, 11:09 AM

moving sizes on tires could make your trans start looking for gears and i am not sure what you are running on the rear axle gear. like i have 4.77:1

Tires: Michelin XRV 255/80R22.5
Wheels: 22.5 x 7.5" Steel or optional polished aluminum

This tire has an overall diameter of 38.2" which is 19.2" radius and is listed with a loaded radius of 17.9". So loaded radius plus radius equals loaded diameter (roughly) So 19.2" + 17.9"=37.1"

playing with this could never late you trans go in to the last gear 6th
if you do this you need to go have your TCM reprogrammed to the right tire size
and this may not help your MPG in the long run

i hope you can find a higher load tire in your size

kketterling · 08-13-2013, 11:46 AM

Not looking to argue about going to 315s from 295s but for anyone considering it here is some additional information I gleaned from Michelin's website.

If you go to Michelin's website: Michelin North America RV Tires Page and then check XZA2 Energy and then hit download brochures you will get information concerning the 315 as to minimum dual spacing and overall width. The chart say's minimum spacing is 13.8". But if you look below the chart there are some notes which state that: Rim listed first is the measuring rim. Overall widths will change 0.1 inch (2.5 mm) for each 1/4 inch change in rim width. Minimum dual spacing should be adjusted accordingly. Since they list the 9.0" rim first I needed to reduce their minimum spacings by .3" which gets me to 13.5" and that is my current spacing for the 295s.

I confirmed this information with Michelin today and they said I would be good to go with the 315s.

Fred Christy · 08-13-2013, 11:50 AM

You will be very happy with them. I am!

deSanford · 08-14-2013, 10:07 AM

Let me start of saying I have not weighted my coach, but after talking with the "Aweight we go" people at the FMCA Albany Or. Rally it was suggested I put 95 PSI in real duals and 105 PSI in the front 275/80R/22.5 Goodyear 670 RV tires. Interesting comment by the fellow who was parked next to me. He had Goodyears and switched to Michelins. He said the stiffer walled Michelins liked to follow the ruts in the road made by the trucks like rail road tracks, because of the stiffer side walls of the Michelins. He said he will no doubt get used to them. He said the Goodyears made the ride less harsh. I guess it is like liking Chevrolets or Fords. deSanford

Mike Canter · 08-14-2013, 11:38 AM

That is totally 180 out from my experience of switching from Goodyears to Michelins. Following ruts in the road is normally caused by not enough positive castor and has nothing to do with the tires. Interesting that the guy says the sidewalls are too stiff on the Michelins because most wantabe tire engineers that pop up occasionally on this forum say they are too soft.

Fred Christy · 08-14-2013, 05:39 PM

I agree Mike. Mine are great and no problems with rutted roads.

deSanford · 08-14-2013, 06:29 PM

WOW you can get all sort of opinions on tires. Matt at the Monaco Service Center in Coburg, Or. also said " Michelins have stiffer side walls compared to Goodyear G670 RV tires". I was told that before we headed up the 5 to Albany for the FMCA Rally. When my neighbor Joe told me about his experience with his new Michelins it seemed to make sense that a softer sidewall like the Goodyear's would not ride in the "truck track". I like Michelins as I have them on 4 of my other vehicles. I still have time as my tires are still pretty new, before I have to put my money on one brand or another. deSanford