Jump to content
bburns8

Question on Tire PSI Front and Rear

Recommended Posts

I have not had my MH weighed/4 corner weighing yet. For now I am going to run what the sticker behind the driver seat states.

The sticker behind the driver seat states 100 PSI for the front and 90 PSI for the rear. 

I have a 2001 Fleetwood Discovery 37 ft 330 CAT MH with 6 brand new Michelin XRV 255/80R/22.5 tires

Why would the front steer tires have more PSI than the rear tires?  The rear has all the weight.

Thanks.

 

Share this post


Link to post
Share on other sites
1 hour ago, wolfe10 said:

Because there are 4 tires in the rear, so each tire is supporting less weight than the 2 tires in the front.

Thank you.  I read posts where others put more PSI in the rear than the front, but maybe they had their coach weighed and it required more PSI in the rear than the front.  Thanks for the quick reply!

Share this post


Link to post
Share on other sites

Michelin should have a pamphlet with a chart showing the correct TP as it pertains to weight for your specific tire.

Share this post


Link to post
Share on other sites

In nearly all cases your front tires will use higher air pressure since there are only 2 vs. 4 in the rear (as mentioned above).  It's all been calculated for you by the manufacturer.....just look it up.  I just put on 2 new front and 2 new tag tires.  The installer set both to 120# (sidewall rating).  I knew right away when I hit the road and the roads here in Houston nearly shook my coach to death.  Once I got home I reduced the tag tire pressure to the proper setting of 90# and I am certain the next trip will be substantially better.  Even the front tire had about 125 cold which I dropped to 120.  The 4 drive tires carry 100#.  That's 3 sets of tires with 3 different pressures and is the correct pressure for each set.  Never set left and right pressures differently even if one side is heavier than the other. 

The proper setting is all tires on the same axle have the same pressure and that pressure is based upon the pressure required on the heaviest side.

Share this post


Link to post
Share on other sites

And that is spot on Bill Adams!  That is one of about one hundred basic things that every motor home owner should know when they leave the dealers lot.  Yes, it's in the owners manual.  If FMCA could put together a general owners manual with basic concise information about tires, electrical systems, water, sewer, diesel engines, transmissions, generators, driving tips and a few other basics, dealers could hand out the booklet for a quick read.  It would of course have the universal disclaimer, the owners manual from the manufacturer always is the best guide.  Maybe FMCA could work together with RVSEF and promote both organizations. 

Share this post


Link to post
Share on other sites

Tom

I am starting to do a series or articles for FMCA magazine just on tires. Not sure when it will start but I hope to cover tires and related items over the upcoming months.

While the idea of a booklet sounds nice there already are a number of publications out there. IMO when buying a new RV you are given an armload of manuals and papers and adding another I think would not accomplish much as most new owners are assuming the coach is ready to go as "prepped" by the dealer as your cars have been for many years. The reality is that an RV is significantly more complex and has many sub-systems, each of which need their own adjustments.

Regarding tires i think you agree that there are a lot of folks out there telling people to get their unit weighed and confirm the air they need. The issue is that you can tell people this but even within FMCA where we have RVSEF offering the service at Conventions only a handful of owners take advantage.

Share this post


Link to post
Share on other sites

The hardest part of obtaining weight is just that... I have thought about pulling onto a CAT scale after refueling but to go in and out for each axle is only part of what I really need to know. Before you know it I will have an angry trucker to deal with while I am blocking the scales, then un hook and re connect the toad....you can see where this is going right, more of a hassle for only half of the information. I might just have to wait for the next rally so I can get to have it weighed, for now when you see a bump in the road bite down so your fillings don't fall out :lol:....honestly its not that bad..

 

Share this post


Link to post
Share on other sites

Some states leave their scales on when they are closed. I used some in Oregon while traveling on the West Coast to get my corner weights.  Also look at the Escapee's as they have different areas that weigh 4 corners.

Share this post


Link to post
Share on other sites

Coaches may be weighed at many Area and National Rallies. To me the only problem with that is having to wait till after the rally is over then get in line while folks are trying to leave. I understand the problem with moving a coach out and then back into your spot. What would be nice if the company could come to your site and all you would have to do was move forward then back. But I also know how heavy the scales are. I wish there was a better solution because it is a great service done by great folks. 

Herman

Share this post


Link to post
Share on other sites

To properly weigh the coaches the ground where the scales are placed must be more firm than grass or gravel and as level as possible.  The weighing services take a great deal of time to scout out a good location with the proper requirements to allow for this and to allow the RV's to get in an out.  Going to a campsite would not be practical.

Share this post


Link to post
Share on other sites

Yep, I understand it was just wishful thinking.:rolleyes:

When we had our Six-State Rally in Shreveport I put the company in an ideal location. It was a drive between a building and a fence. Coaches were able to circle around, with plenty of space to wait their turn then pull out make an easy turn to an area beside the exit road. There was ample space to park, hook up and pull into the exit road. It only took each coach no more than 10 minutes to get weighed when their turn came.  

Bad thing was that I was so busy with the Rally Wrap-up I couldn't get mine done. :(

Oh well, like the Carol Collins song said, "Maybe next year."

Herman 

Share this post


Link to post
Share on other sites

Please sign in to comment

You will be able to leave a comment after signing in



Sign In Now

×
×
  • Create New...