How to make your RV tires last longer

The part of RV life we love to hate: taking care of or replacing old, damaged or worn out tires. One thing is true about tires in RV application: No one likes having to replace them. Some people dislike dealing with their RV tires so much they may forget that proper care and maintenance can allow us to run our tires longer.

Different vehicle tires need different care

First, we need to understand some facts that you may not have been told or even thought about: Tires on different vehicles need different care. Some may realize that the tires on passenger cars seem to last longer and have fewer problems than the tires on their RV. But just because your car tires are round and black and the tires on your 40’ Class A diesel pusher are round and black, there are significant differences in both tire design and construction, and in the loading and service you place on your tires.

As the end user, there isn’t anything you can do about tire construction other than pay attention to the information you are provided. All tires have a short description with the number and type of reinforcement materials in the tire. You will find this on the tire sidewall. It will say something like, “Sidewall 1 layer (or ply) steel, Tread 3 layer (or ply) steel plus 1 layer Nylon”—if that was the construction in your tire.

I suggest everyone go out and “read” the material list on your tires. If you have 19.5 or 22.5 diameter tires on your RV, you probably only have steel as reinforcement. If you have LT-type or ST-type tires, the materials are most likely polyester and steel, plus possibly nylon. Your passenger-type tires will be polyester and steel plus possibly nylon. I would consider ST-type and LT-type tires that include nylon on top of the steel belts as possibly better than those without the nylon cap ply.

Reserve Load for tires

The things you, as the user, can control are load and inflation. Your passenger car tires probably have 25% to 35% “Reserve Load”. I suggest you review THIS post on “Reserve Load” in RV service. The tires provided on many RVs by the manufacturer probably provide a theoretical 10% reserve. I say “theoretical” because the reality is that half of the RVs that have had each tire load measured by RVSafety or Escapees have discovered they are overloaded and/or under-inflated. That 10% figure assumes you are always properly loaded and inflated.

You do not need to get your RV weighed every trip if, when you got it on a set of scales, you were at the heaviest you ever expected to be and confirmed your tires were no more than 95% of the tire load capacity for your inflation.

Inflation

So we are left with inflation. There are Load/Inflation tables available for all tires. If you have Michelin brand tires, you should use their tables, available HERE. All other brands can use the tables I have posted on my blog, as everyone else uses the same formula. If you look, you will see that all tire companies provide the same PSI rating for the same load on the same size and same Load Range tires.

So, how do you select the appropriate inflation? The inflation in the tables is the MINIMUM PSI required to support the stated load. Ideally, you would inflate to a level that would give you a Reserve similar to what you have with your car. However, I am not aware of any RV company selecting a tire that would allow that since it would cost them more than the minimum requirement.

Remember: you always go up to the next level PSI if you exceed the stated load, even if you only exceed that load by 1 pound. DO NOT TRY and calculate for a PSI between cells in the table.

Tire age

This topic can be confusing as we are trying to balance the cost of a set of tires against the possibility of having a tire failure. The best we can do is to first establish a maximum age based on the DOT serial date code, and that would be 10 years.

But that would be for tires with a normal 20% to 25% reserve capacity. When you reduce that capacity, it has been suggested that you have cut three to four years off the maximum tire life. We can’t be more specific as the age of your tires depends on the heat history over their life. This would include operating temperature and even the temperature when parked or stored. Remember the “rate” a tire ages doubles with every increase in temperature of 18°F.

Ensuring you always have the air pressure you want would include the use, proper programming, and annual testing of your TPMS system.

Roger Marble

MORE POSTS FROM ROGER

• My RV tire pressure is showing a significant increase. Is this OK?
• Is the tire pressure too high?
• Should you adjust tire pressure when temps get colder?
• Do not adjust your tire pressure for ambient temperature
• Understanding what temperature change does to tire pressure

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If you have tire questions, check out Roger’s Blog as well as his posts on RVtravel.com. There are hundreds of posts covering everything to do with tires.

If you still have a question for Roger after searching the above posts, send your inquiries to him using the form below.

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