Community Forums

georgetown350 · 06-22-2007, 03:08 PM

Just wondering if my tire pressures are correct. I run all tires at 98 psi. 90 is recomended but I here 99 % of blowouts are from underinflation or overloading so im to scared to go that low.

gross weight rating is 22000 and I weighed in at 18400. 6481 front and 11948 in the rear. with adjustments all 4 corners will be somewhat even.

I have 235/80 p225 110 max. michelins.

thanks

georgetown350 · 06-22-2007, 03:08 PM

Just wondering if my tire pressures are correct. I run all tires at 98 psi. 90 is recomended but I here 99 % of blowouts are from underinflation or overloading so im to scared to go that low.

gross weight rating is 22000 and I weighed in at 18400. 6481 front and 11948 in the rear. with adjustments all 4 corners will be somewhat even.

I have 235/80 p225 110 max. michelins.

thanks

MikeT · 06-22-2007, 03:43 PM

You are over "aired"

Michelin load table

The table show pressure and axle load.

AFChap · 06-22-2007, 05:59 PM

"90 is recommended" by what? I suspect that is the placard in the MH? Based on the Michelin chart, that would be the recommended tire pressure if you were running at your maximum weight of 22k (actually gives you a slight cushion). The vehicle placard normally is based on your maximum weight, or GVWR.

If I am reading the right tire on the chart, (235/80R22.5 LRG XDE, XRV or XZE) with the weight you indicate you are currently running, even 90 is overinflated, which can make the coach ride harder and the steering flakey. 98 just makes is more so. It is better to be overinflated for weight than under, but with the chart recommended PSI for your weight being 70 psi, 98 is sure more than I would run. I always pad my recommended psi's by at least 5. So, with your weight and tires, I would probably run them around 80 psi.

JMHO...

georgetown350 · 06-24-2007, 02:51 PM

90 is the recomended psi printed on the inside kitchen cupboard door. I presume you are right that it is based on the gvwr of 22000.

Rv dealership put 110 in the tires for me. Rough ride.

After reading your posts, while away for the weekend I have dropped down to 90 psi. The ride seemed smoother coming home. I will study that chart and continue to weigh our rig as wifey continues to load up the cargo spaces.

Thanks for the replies ( very helpful )

Steve

georgetown350 · 06-24-2007, 03:13 PM

According to the Michelin chart if I were at my gvwr of 22000, I should run the front tires at between 75 and 80 and the rear duals between 85 and 90 yet the kitchen cabinet tells me 90 all around.

Seems like they are padding the front tires quite a bit.

SargeW · 07-06-2007, 12:21 PM

AFC is right. The placard on my rig recommends 110 in the fronts. After I weighed it I dropped it to 95 in the fronts and 85 in the rear duals. That is still over inflated for what I am carrying, but I do allow for a cushion as well. The ride is much better since I am now running the correct air pressure. It will also help to keep these expen$ive tires from prematurly wearing out.

Dick L · 07-08-2007, 10:00 AM

I also agree with AFC. The placards in Motorhomes are genaric and the ONLY REAL way to know how much air pressure is needed, is to do a four cornered individual weighing and adjust according to your tire manufactors charts.

Also be careful that you have the exact correct listing for you tires. I have seen old and new listings for the same tire with the same load ranges so also note the maximum weight @ the maximum air pressure on the tire sidewall and refer to the charts. You may be surprised to see some differences in the weight ratings @ specific air pressures.