When should you replace your tires?

Saw the following question on an RV forum from a motorhome owner.
"Does anyone ever just replace their front tires after 7 years? It seems that a tire failure on the front is much worse than the back. If the tires have a lot of tread and no sign of cracking, why replace the back ones?"

One reply correctly said, "There's more to consider than age. Were they properly inflated? Did you bang into curbs to damage the sidewalls? There are many failures due to improper operating conditions. Not just age."

I would first ask if you know the "life experience" of the tires:

Did the RV have a previous owner?
While they may claim they always checked inflation, can we be 100% certain?
Did you purchase the tires direct from a major tire company and know the complete use history?
Have you confirmed your load on all the tires from day one?
Did you ever discover one of your tires 20 or 30 psi low one time?

There are many things to consider, but if you are confident the tires have always been properly inflated for the actual load the following should help.

"Blowouts" (look at the picture at the top of my page), or more properly Run Low Sidewall Flex failures, happen because of running on low inflation. This can be avoided with the use of TPMS.

Belt separations, which are much less common on commercial grade tires, may occur after the rubber at the belt edges degrades due to cumulative damage from heat.

UV does not affect the internal structure of tires and external cracking is only one symptom of exposure to sunlight. I consider external cracking like having a person run a temperature. Having a temperature is just a symptom of some other illness, usually an infection. You can be seriously ill but not be running a temperature. Think of heart disease or cancer as two things that can kill you but don't cause you to run a temperature.

The suggestion on when to replace tires is only based on probability, as it is impossible to know just how much damage has been done to the components of a tire. The general suggestion is to have tires closely examined by a tire expert at 5 years and each year after that. Tires should be replaced at 10 years no matter what is visible on the surface of a tire.

I wrote a blog post on a suggested inspection and "step replacement" concept. A version of this suggestion could result in your keeping newer tires on the front, which in theory should improve your chances of not having a belt separation on the front. Of course also running TPMS will improve your chances of not having a Run Low Flex Failure too.

##RVT803