Tire Age Matters More Than Tread Depth
Tires are your only contact with the road, and they degrade from the inside out — even when they're sitting still. A tire that looks fine on the outside may have internal cracking, brittleness, or structural degradation that isn't visible during a normal walk-around inspection. That's why age is one of the most important factors to track, and why the DOT date code on every tire exists.
Every tire sold in the United States is required to have a DOT code molded into the sidewall. The last four digits of that code are the date code: the first two digits are the week of manufacture, and the last two are the year. A code of 3521 means week 35 of 2021. That's the number this tool decodes.
Where to find it: look on the tire sidewall for the letters DOT followed by a series of characters. The date code is the last four digits of that string — a two-digit week number followed by a two-digit year. It may be on the inboard side of the tire, which means you may need to look from underneath or use a flashlight. On dual rear tires, the inner tire's date code often faces inward and requires removing the tire or using a mirror to read.
RVTI guidance for motorized units. Inspect at 5–6 years and follow manufacturer replacement recommendations.
Towable tires carry static loads, age faster in storage, and have less heat dissipation than motorized tires.
At 6 years and beyond, replacement should be seriously considered regardless of tread depth or appearance.
Decode Your Tire Date Code
Most RV tire sidewalls include a DOT date code showing the week and year the tire was manufactured. This tool decodes the last four digits.
- Find the DOT code: look on the tire sidewall for the DOT marking followed by a series of characters. The date code is the last four digits of that string.
- Enter four digits: the first two digits are the manufacturing week and the last two are the manufacturing year. Example: 3521 means week 35 of 2021.
- Check tire age: the tool calculates how old the tire is from the manufacturing week to today.
- Verify before replacing: age is one factor. Also inspect for cracking, bulges, uneven wear, and sidewall damage, and follow the tire and RV manufacturer's replacement guidance.
Tires manufactured before 2000 used a three-digit date code. If your tire has only three digits at the end of the DOT string, the tire is from the 1990s or earlier and should be replaced immediately regardless of condition.
Check Tire Age
Enter the last four digits of the DOT date code.
Age Is The Starting Point. Condition Is The Deciding Factor.
A date code tells you when a tire was made. It does not tell you how it has been stored, whether it has been overloaded, or whether it has developed internal damage that isn't visible from the outside. Every tire inspection should include a physical condition check — and that inspection should happen before every trip.
- Sidewall cracking: look for fine cracks or crazing in the rubber, especially in the sidewall and around the bead area. Some surface checking is common with age, but deep or wide cracks indicate the rubber compound is breaking down. Do not operate an RV on tires with significant sidewall cracking.
- Bulges or bubbles: a bulge on any part of the tire is a sign of internal structural failure. A tire with a bulge should be taken out of service immediately — it is not safe to drive on.
- Uneven tread wear: wear that is heavier on one side, in the center, or in patches can indicate inflation problems, alignment issues, or suspension problems. A tire wearing faster than the others on the same axle deserves attention beyond just tire replacement.
- Cupping or scalloping: a wavy, scalloped wear pattern usually indicates a suspension or shock absorber issue, not just a tire problem. Have the suspension inspected along with the tires.
- Tire pressure: always inflate to the manufacturer's load chart PSI for your actual axle weight — not the maximum pressure rating molded on the tire sidewall. Those are two different numbers. Underinflation generates heat and causes internal damage that may not be visible. A tire that has lost more than 20% of its recommended inflation pressure should be treated as flat and professionally inspected before further use.
- Missing or cracked valve caps: use metal valve caps with an inner rubber gasket. Plastic caps may not seal properly at the higher pressures used on RV tires.
Don't Drive On A Questionable Tire
An RV tire failure at highway speed is a serious safety event. The cost of an early replacement is never more than the cost of a blowout. If any of the following apply, do not drive the RV until the tires have been professionally evaluated.
- Any tire is 6 or more years old. Have the tires professionally inspected and follow the replacement recommendations from both the tire manufacturer and your RV manufacturer before continuing travel.
- Any tire shows a bulge, bubble, or sidewall deformity of any kind. Take it out of service immediately.
- Any tire shows significant sidewall cracking, deep checking, or visible cord exposure.
- One tire on an axle is wearing significantly faster or differently than the others — the cause may be a suspension, alignment, or load distribution problem that affects safety beyond the tires themselves.
- You have experienced a blowout or run-flat event. The wheel, hub, and surrounding brake components should be inspected before returning to service, not just the tire replaced.
- You cannot read the DOT date code because the tire is mounted with the code on the inboard side. Have a shop or technician read the inner tires during your next service visit — operating on tires of unknown age is not a safe practice.
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