Care of tires

[kennpriebe]

Hello there; I am new to motor home use. I purchased a 1991 Bounder with Ford 460. It appears to have good tires and I was told they were fairly new. My questions are: How much pressure should I have them at? This is a 28 foot unit with duals on the back. Should there be a difference in the front vs. rear pressure? What is best when it sits for months at a time--up on jacks or just sitting? If up on jacks will that affect the jacks performance over time? Also, how about use of tire shine or products that foam and make the tire look better? I would appreciate your advice.

Thanks, Kenn

[AFChap]

Check the DOT number on the tires for the mfg date -- the last four digits will tell you what "fairly new" means. i.e. 2403 would indicate tire mfg date of 24th week of 2003. You can look at my website at Tire Date Codes/Tire Care to learn more on how to read the tire date codes (and some other tire care recommendations).

Unless someone has the identical rig loaded with the same stuff and has the same brand, size & model tire, none of us can tell you how much pressure you should carry. The only way to know is to weigh the rig as you normally travel, each corner or at least each axle, and then use the tire mfg's chart to figure out the recommended pressure. Normally, the front will require 5 to 10 psi more than the rear, but you are just wild guessing until you know the rig weight.

My MH has HWH leveling jacks, and the mfg says to store the rig with the jacks down to take some pressure off the tires. HWH also says not to lubricate the jack rams -- you need to check with your jack mfg to see what they say. It is also recommended to cover the tires to protect them from UV detirioration, and to use vapor barriers under the tires and to park when they will never stand in water after a rain.

Most tire dressings that "make the tire look better" actually do more damage than good. If you do use something, make sure it does not contain any pertoleum products. About the only one I know to be safe to use is 303 Protectorant, though there may be a few others.

Enjoy the RV !!

[kennpriebe]

Hi there.

Thanks for the information. I will have to weight the unit, which I have not done yet.

Kenn

[nbounder]

Kenn - check the driver side interior wall at about hip level for a label that tells the mfr recommended tire pressure. My 95 Bounder requires 80 pounds cold inflation pressure. I have my doubts about this 'weigh it at the corners' stuff. Figger that 100 gallons of water and 80 pounds of fuel weigh around 1400 pounds. Leaving home it's usually full, and less than half that coming back. This means a different set of pressures for each direction,then add in the fact that the holding tanks are likely not inthe same place as the water & gas tanks, so the balance will certainly change. Perhaps some tire guru can splain how that corner weighing takes those factors into account. Till then, I'll stick with the 'door jamb' numbers. Tire gurus, where art thoust?

[AFChap]

The "door jamb" numbers are better than nothing, and probably better than the max psi on the tire sidewalls, but they don't take into account how you have loaded the coach, and with what. AND THEY DON'T TELL YOU HOW CLOSE TO YOUR MAX WEIGHT YOU ARE. The door jam numbers also are accurate only for the original tires. For instance, my coach came with Michelin tires. I replaced them with Continentals in the exact same size and load range. When I compare the Michelin chart to the Continental chart I find that the Continentals require 5 pounds more than the Michelins at the same weight. The "right" pressure could be much more than 5 psi if you have a different sized tire on the coach than was on it originally.

A simple axle weight will tell you most of what you need/want to know. What the four corner weight does is alert you to imbalance from one side to another. You want have it weighed loaded as YOU normally travel --- all your normal stuff, full fuel, however much water you would normally carry, etc. My coach is heavier on the left front and the right rear, easily explainable when I note where slide rooms are, all the batteries, basement ac/heat pump, etc. That kind of imbalance is not at all unusual. Knowing where my heavy corners are, I can attempt to balance the coach a little better when I load stuff in storage compartments, etc. When you figure the tire pressure for the axle weight, you use the recommended pressure for the heavier side so you are sure that all tires have at least as much pressure as they need for the load they are carrying (none are underinflated, which causes overheating and tire failure).

I very rarely travel with more than apx 1/3 tank of water unless I know I am headed somewhere I will not have shore water -- why pay to carry extra water??

If you have never weighed you coach, you probably have little real idea of how much cargo carrying capacity you have. Even when you have the factory numbers, they don't take into account dealer & owner installed options. Several years ago, many MHs were very close to their max weight right out the factory door, some were actually overweight (some early Bounders were in that category, later Bounders were/are much better ...sorry, I don't know when they got better). There are still some new rigs that have very little CCC -- add water and a couple of normal sized people and their suitcases, and you may be pretty much maxed out! You need to know how close your rig is to it's max capacity.

[kennpriebe]

Thanks. Great Information.
Kenn

[kennpriebe]

Thanks for that information. Very helpful.

Kenn