Key Takeaway
Every tire has a date of birth stamped on the sidewall. Here's how to find it, read it, and know when a tire is too old to trust.
Every tire sold in the United States has a DOT date code stamped into the sidewall. Those four digits tell you exactly when the tire was manufactured — information that matters a lot more than most owners realize, especially in Florida.
Here's how to find it, read it, and use it.
Where to Find the DOT Code
Look at the sidewall of the tire. You'll see a long string that starts with "DOT" followed by a series of numbers and letters. The whole code looks something like this:
DOT U2LL LMLR 2319
The last four digits are what you care about: 2319.
Important: The DOT date code is usually on only one side of the tire. If you look at the outer sidewall and don't see it, check the inner sidewall. On trailer and dual-wheel applications, this can mean crawling underneath.
How to Read the Four Digits
The last four digits are split into two pairs:
- First 2 digits — Week of the year the tire was made
- Last 2 digits — Year the tire was made
So 2319 means the tire was manufactured in week 23 of 2019 (early June 2019).
Other examples:
- 0122 = Week 1 of 2022 (early January 2022)
- 4518 = Week 45 of 2018 (early November 2018)
- 3224 = Week 32 of 2024 (early August 2024)
Wait — What About Tires Before the Year 2000?
Before 2000, DOT codes used three digits instead of four. A code like "238" would mean week 23 of either 1988 or 1998 — you had to figure out which decade from context.
If you see a three-digit DOT code on a tire in 2026, that tire is at least 26 years old. Replace it immediately regardless of how the tread looks. Rubber doesn't last that long — period.
Why the Date Code Matters
Rubber degrades over time whether the tire is being driven or just sitting. Oxygen breaks down the rubber compound. UV light accelerates it. Heat accelerates it faster.
Every major tire manufacturer and the National Highway Traffic Safety Administration recommend replacing tires every 6 years or less, regardless of tread depth. Some manufacturers say 5 years for specific applications (RVs, trailers).
In Florida, the heat and UV make this even more urgent. We see tires that are mechanically sound, have plenty of tread, and look fine from the outside — but are structurally compromised because they're 7+ years old and sat in Florida storage lots for most of that time.
Age Guidelines by Tire Type
Passenger car tires: 6 years max, even with good tread. Replace by age at the 6-year mark.
RV tires (Class A, Class C, fifth wheels, travel trailers): 5–7 years max. In Florida, we recommend 5–6 years due to heat and UV exposure.
ST (trailer) tires: 5 years max in Florida. National spec is 5–7 years, but Florida cuts the upper end off.
Commercial truck tires (semi, box truck): More miles-based than age-based for fleet vehicles in daily service, but casings past 6 years in service should be inspected carefully.
Spare tires: Check them! A spare tire that's been mounted on the back of an RV or under the bed of a pickup for 10 years is not a safety backup — it's a liability.
What to Do When You Find an Old Date Code
- Check all tires on the vehicle. Date codes can differ tire-to-tire if the vehicle has been serviced multiple times.
- Compare to your replacement window. 5 years for Florida RVs/trailers, 6 years for most others.
- Look for physical signs of aging. Sidewall cracking, dry rot, chunks missing, discoloration.
- Plan replacement. Budget it if not urgent. Do it immediately if you're seeing any sidewall cracking.
The Florida Factor
If you store an RV or trailer outdoors in Florida — especially east of I-95 where salt air adds to the damage — the national date-code guidelines are too lenient.
What we see in our service area:
- Tires that pass a visual check but fail a date-code check
- Owners surprised to find out their "almost new" tires are actually 6 years old
- Blowouts on I-95 from tires that had plenty of tread
Do the date-code check every spring before trip season. It takes 60 seconds per tire.
60-Second Date Code Check
- Walk to the tire
- Find the DOT code on the sidewall (may need to check both sides)
- Read the last 4 digits
- First 2 digits = week of year, last 2 digits = year
- Math: Is the tire 5+ years old? Plan replacement. 7+ years old? Replace now.
Repeat for every tire including the spare. You'll know in 5 minutes whether your vehicle is on safe rubber or overdue.
If You Find Old Tires and You're in Central Florida
K & W Mobile Tire Service handles tire replacements on-site across Volusia, Flagler, and Brevard Counties — at storage lots, campgrounds, driveways, fleet yards, and job sites. No need to drag the rig anywhere. Call (386) 566-7339 with your tire size and location and we'll quote the replacement.