Tires are a critical component to check during a pre-purchase inspection or routine maintenance. One thing I often find during a RV inspection is old tires on vehicles being sold. RV tires seldom wear out due to high mileage. Many RVs being sold have original tires. When low mileage RVs are sold, the original tires are still on the RV. General tire literature recommends replacing tires after six years.
Tires installed on the RV new are usually older than the RV itself. The tires come out of stock that may be months or more older than the RV. One of the ways to determine tire age is to look at the DOT stamp on the tire. Following the DOT stamp are a series of numbers inside small ovals. The last oval contains the date information for the tires. For example, 337 would indicate that the tires were manufactured in week 33 of 1997. Beginning in 2000, you will find four numbers. The first two are the week of manufacture and the last two are the year of manufacture.
Tires are designed to roll. The rubber compound has been designed to create a lubricating effect within the rubber compound when the tires are rolling and at operating temperature. Using the tires (and RV) is a good thing because it keeps the rubber lubricated and pliable.
I often see very low mileage RVs with tires that have excellent tread but show dangerous signs of tire rot. Outside exposure decreases tire life when the tires are stationary for a long period of time. Tires stored inside will also show signs of tire rot over time if they are not used.
The key message is use that RV and keep checking the tires for cracks around the sidewall. Be prepared to replace the tires around six years, regardless of the amount of tread remaining if you see cracks forming on the side wall of the tire.