Tire pressures

[LoriL]

Ok, we're new owners and my husband (he's writing this note) is an engineer so things might get 'anal' fast with our new unit! We have a 2000 mountain aire which was wheel weighed on 9/2011. At the time, the previous owner had pressures set at 110# all the way around. Based on the weigh data he dropped pressures to 115# front and 100# rear. The tires are 275/70-22.5 Michelin XZE2+. My concern is that the MINIMUM rating is 100#, so at 100# on the rear do I have to worry about the rears rubbing against each other? As I've read this would be bad!!

Thanks for any thoughts on this.

[nightriderrv]

I always run the tire psi per the specs on the sidewall @cold temp the tires should not rub they might touch if the unit is moving up and down like going down the road. only time I seen then really touch if they were under psi really low that will make the sidewall wider.

["007"]

Welcome to irv2 & this forum.
Read this thread for sound information.
You have had your four corners weight than follow the tire pressure tables for your size tires and use the pressure Michelin recommends.
You will find they will be lower pressures and a softer safer ride.
Riding the maximum tire pressure on sidewall tires will cause a possible blowout because the pressures will increase 15 to 20 lbs while your driving on road.
Some people do add 5 extra lbs in tires above Michelin's tables with good results.
I have tires that are now 10 years old on duels, just changed fronts because of tire wear, by following tire pressure tire recommendations by either tire MFG Michelin or Goodyear.
I have followed this advise on all my motor homes and never had a tire failure or blowout.

[RickO]

Hi and welcome to the fourm. As 007 points out there is a wealth of reading material on this topic so check out the thread he provided or use our search feature to keep you supplied with reading material for a week!

Bottom line is that I would not trust what the previous owner had done and I would load up the coach with full tanks ready for travel and get it weighed. Then you go to the Michelin web site and their inflation tables will tell you exactly what the PSI should be for each of your axles. I then add 5 PSI "just because". I have a 40DP and believe I have the same tires, and I run 90 front and 95 back.

If you can't find the XZE's on the RV inflation table, they told me to use the XZA3 table.

Best of luck.

Rick

Originally Posted by 007";1226027]Welcome to irv2 & this forum.
[B][URL="http://www.irv2.com/forums/f103/tire-pressure-115624-2.html#post1091032

Read this thread[/URL][/B] for sound information.
You have had your four corners weight than follow the tire pressure tables for your size tires and use the pressure Michelin recommends.
You will find they will be lower pressures and a softer safer ride.
Riding the maximum tire pressure on sidewall tires will cause a possible blowout because the pressures will increase 15 to 20 lbs while your driving on road.
Some people do add 5 extra lbs in tires above Michelin's tables with good results.
I have tires that are now 10 years old on duels, just changed fronts because of tire wear, by following tire pressure tire recommendations by either tire MFG Michelin or Goodyear.

[Mr_D]

According to the tire manufacturers you should never go below the lowest pressure on their charts.
Also, the pressure on an RV tire sidewall is not the maximum it should ever have, rather it's the minimum to support the maximum rating of the tire. You can safely go slightly above that

PS: I got out of engineering in about 1988 and retired in 1998 from the WA DOT.

[GaryKD]

Hi LoriL,
I have the same size Michelin tires as you. At 95 PSI in the rear tires they will carry 20K lbs. This is, most likely, the GAWR of the rear axle. That is the PSI in my rear tires. I am GAWR on the rear axle. On the front, I run 105 PSI. The chart calls for 100 PSI because of the weight. Added 5 PSI per a previous post.