How to read an RV tire’s age, and when to replace it

Most RV tires don’t wear out. They age out. A motorhome sits for weeks at a time, carries a heavy load, and spends its life in the sun, so the rubber can crack and weaken long before the tread is gone. That is why the date on the sidewall matters more than the tread depth on most coaches.

This guide shows how to read the date code on any tire, what the age milestones mean, and how we track the tires on our own 2020 Tiffin Allegro Red 33AA.

On this page: Read the date code · When to replace · What to inspect · Our coach’s tires · FAQ

How to read the DOT date code

Every tire sold in the US carries a DOT number on its sidewall. It starts with the letters DOT, and the last four digits, often inside an oval, are the date the tire was made.

• The first two digits are the week (01 to 53).
• The last two digits are the year.

So 3319 means the 33rd week of 2019, which is mid-August 2019.

The two or three characters right after “DOT” are the plant code, which identifies the factory. The characters in between identify the size and the maker’s own details. They don’t affect the tire’s age.

A few things that trip people up:

• The full code may be on one side only. The law requires the full DOT number on just one sidewall. On a dually’s inner tire, it may face the other tire, so use a flashlight and a mirror, or check while the coach is on a lift.
• Three digits means it’s from before 2000. Before 2000 the date code was three digits. A tire with a three-digit code is more than 25 years old and should come off.
• Every tire has its own date. Don’t assume a set of six was made the same week. Read each one.

When to replace RV tires

There is no federal age limit for tires on a private motorhome in the US. The limits come from the tire makers, and they are the authority for your tires. Here is how the milestones usually line up:

• Michelin says its tires can stay in service up to 10 years from the date of manufacture, as long as they pass a professional inspection at least once a year from year 5 on. Past 10 years, replace them even if they look fine.
• Other makers set their own rules, so check the warranty booklet or website for your brand.
• Many motorhome owners replace tires around 7 years, earlier than the maximum, because a front tire failure on a Class A is so dangerous.
• Replace any tire right away if it has a bulge, exposed cords or deep sidewall cracks, whatever its age. If one has been run seriously underinflated, have a tire professional inspect it off the wheel before it goes back in service.

What to check at each inspection

• Sidewall cracks. Fine surface crazing is common on older tires. Cracks you can catch a fingernail in are not.
• Bulges, bubbles or cuts on the tread or sidewall.
• Tread depth and wear pattern. Uneven wear points to alignment, balance or pressure problems.
• Pressure, set from your actual weight. Weigh the coach axle by axle (or wheel by wheel), then look up the pressure for that load in the tire maker’s load and inflation table. If one side of an axle is heavier, set both tires on that axle to the pressure for the heavier side. The number on the sidewall is the pressure for the tire’s maximum load, not the target.
• Valve stems and caps, especially the long stems on dually inner tires.

Covering the tires while the coach is parked keeps the sun off them and slows the aging.

A real example: our Tiffin’s tires

Our coach is a 2020 Tiffin Allegro Red 33AA on a Freightliner XC-M chassis. It runs six Michelin 275/80R22.5 tires, two on the front axle and four on the rear dually.

The date code on all six is 3319: week 33 of 2019, about seven years before this guide was written. The coach is a 2020 model, but its tires were built in the summer of 2019. That is normal, and it is why the date code matters more than the model year.

At seven years, these tires are in the window where Michelin calls for a yearly inspection and many owners start planning replacement. They can stay on as long as each yearly inspection passes, up to 10 years from manufacture.

Track tire age in Wrench Wise™

In Wrench Wise™ you add each tire by its position on the coach, front left through the four rear duals, and type in the DOT code. The app reads the week and year from it and keeps the age current, so you don’t have to do the date math every season. Each tire shows a status that follows the same milestones as this guide:

• Safe: under 5 years
• Caution: 5 to 7 years
• Replace soon: 7 to 10 years
• Replace now: 10 years or more

Our six tires changed from Caution to Replace soon on their seventh birthday, without anyone having to remember. Tire tracking is free. With Pro, the app also checks your tires against NHTSA recalls in the US, and a tire with an open recall is flagged first, whatever its age.

Wrench Wise™ is not affiliated with Michelin, Tiffin Motorhomes or Freightliner. This guide describes one owner’s coach. Your tire maker’s guidance and a qualified tire professional are the authority for yours.