Car owners are used to replacing tires when the tread wears down. Motorhome owners can't think that way. A Class A coach often sits for weeks or months between trips, so its tires can look nearly new on the outside while the rubber inside has aged to the point of failure. A blowout on a 40-foot coach on I-75 or GA-400 is dangerous and can do serious damage to the coach itself.
Why motorhome tires age instead of wear out
They sit a lot
Rubber contains compounds that help protect it from aging, and those work best when the tire is rolling and flexing. A tire that sits still in one spot for months ages faster and can develop flat spots and cracking.
Georgia heat and sun
Long, hot summers and strong sun break down rubber, especially on the side of the coach facing the sun in storage. You may see small cracks in the sidewall, sometimes called weather checking.
Heavy loads
Large coaches put a lot of weight on each tire. Running a tire with too little air for the load builds heat, and heat is what destroys tires from the inside.
How to read a tire's age
Every tire has a DOT code on the sidewall. The last four digits are the week and year it was made. For example, 2421 means the 24th week of 2021. Check every tire, including the inner duals at the rear, which are easy to forget. Sometimes the full code is only on one side, so you may need to look at the inside sidewall.
Tire makers and the RV industry give different guidance on age. Many recommend regular professional inspection once tires reach a certain age and replacement after a set number of years, no matter how much tread is left. Check your tire manufacturer's recommendation and your coach's owner's manual, and don't run tires past what they advise.
Before every trip
- Check pressure cold, before driving, with a gauge you trust. Use the pressure for your actual weight from the tire maker's load chart, not just the number on the sidewall, which is the maximum.
- Look at the sidewalls for cracks, bulges, cuts or bubbles.
- Check the tread for uneven wear, which can point to alignment or inflation problems.
- Look at the valve stems and extenders, especially on duals, where leaks are common.
- Use a tire pressure monitoring system if your coach has one, and make sure all sensors are reporting.
Weighing your coach
The most accurate way to set pressure is to weigh the coach loaded for travel, ideally each axle or each wheel position. Many owners are surprised how much weight water, fuel, gear and a full pantry add. Once you know the weights, use the tire manufacturer's chart to set pressure correctly.
Storage habits that help
- Cover the tires from direct sun.
- Park on a clean, firm surface; some owners use boards or pads.
- Keep tires at the proper pressure while stored.
- Move the coach occasionally if you can, so the same spot on each tire isn't always loaded.
When to get a second opinion
If you're buying a used coach, tire age should be part of the price. Ask about it, and make it part of a pre-purchase inspection. If you own the coach, add tire dates and condition to your preventive care routine and your spring prep, so you're never surprised on the road.
RV Action Express helps coach owners around Cumming, Lake Lanier and North Atlanta stay ahead of the problems that cut trips short. Call (866) 292-6838 or request service.
Questions about this topic
Possibly. Age matters as much as tread on a motorhome. Check the date codes and your tire manufacturer's guidance, and have older tires inspected even if they look good.
It depends on the actual weight on each axle. Weigh the coach loaded for travel and use the tire manufacturer's load and inflation chart. The number on the sidewall is the maximum, not the recommended pressure.
Not always. Some aging happens inside the tire. Cracks and bulges are warning signs, but a tire can look fine and still be past its safe age. Always check the date code.
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