The last four digits of the DOT code are the week and the year your tire was made — 2419 is the twenty-fourth week of 2019. That part every decoder does.
For tires supplied under Lionshead’s ST radial tire warranty, the five-year term starts at manufacture. Other suppliers may use different terms. The tool estimates that warranty window alongside age; it does not decide whether the tire is fit to use or whether a claim will be accepted.
Four digits on the sidewall
Read the DOT code, then find out what it cost you
The complete code may be on the opposite sidewall. The last four digits identify the manufacturing week. Warranty results below estimate Lionshead’s ST radial tire term only; confirm the policy that applies to your tire.
The answer
Against the maker's own term
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What the cover was for
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Replacements in your size
Castle Rock ST205/75R15 Radial Trailer Tire, Load Range C
ST205/75R15 · Load Range C · 6 ply · 1,820 lb at 50 psi
Check price at Lionshead Tire & Wheel(opens in a new tab)
Westlake ST205/75R15 Radial Trailer Tire, Load Range C
ST205/75R15 · Load Range C · 6 ply · 1,820 lb at 50 psi
Check price at Lionshead Tire & Wheel(opens in a new tab)Westlake ST205/75R15 Radial Trailer Tire, Load Range D
ST205/75R15 · Load Range D · 8 ply · 2,150 lb at 65 psi
Check price at Lionshead Tire & Wheel(opens in a new tab)Castle Rock ST225/75R15 Radial Trailer Tire, Load Range D
ST225/75R15 · Load Range D · 8 ply · 2,540 lb at 65 psi
Check price at Lionshead Tire & Wheel(opens in a new tab)Westlake ST225/75R15 Radial Trailer Tire, Load Range E
ST225/75R15 · Load Range E · 10 ply · 2,830 lb at 80 psi
Check price at Lionshead Tire & Wheel(opens in a new tab)How to read the code
Illustration only: the complete TIN is not reproduced. The date may be on the opposite sidewall. Tire size and load markings are separate.
Example date code: 2419
16–22 June 2019 under the Sunday-to-Saturday calendar-week rule. The code identifies a week, not an exact day.
Record each tire’s code, including the spare. Use a camera if the inner marking is hard to read; secure the parked vehicle before inspection.
Age, warranty and condition answer different questions. A supplier’s five-year warranty is not a universal replacement interval or proof that a tire remains usable.
Sources: 49 CFR 574.5(b)(3) and NHTSA tire guidance.
Find the final four-digit group of the DOT Tire Identification Number (TIN). Under 49 CFR 574.5, the first pair identifies the manufacturing week and the second pair the year. Weeks run Sunday through Saturday, starting with the year’s first full week. The regulation’s example, 0109, covers 4–10 January 2009.
The clock starts before you own it
Lionshead’s warranty sets a five-year term from the date code for its ST radial tires. A tire bought two years after manufacture has roughly three years of that term remaining. Its separate No Excuses guarantee uses a twelve-month purchase-based period.
Read the date before buying, and confirm which supplier’s policy applies to the particular tire. The calculator’s month estimates use the manufacturing week; the date code does not reveal the exact day.
What the cover is actually for
Lionshead covers qualifying defects in materials and workmanship, subject to its exclusions and verification process. Visible damage does not establish the cause or guarantee an accepted claim. The current policy requires written notice within seven calendar days of discovering, or reasonably being expected to discover, a defect, with the specified claim documents.
How old is too old for RV tires?
Use the replacement and inspection guidance from your tire and vehicle manufacturers. The five-year warranty used here is not a universal tire life. This page does not assign a replacement age from a warranty term.
NHTSA’s tire-aging guidance explains that storage, environment and use affect aging, and that appearance alone cannot reveal it. Low-use RV tires and spares need attention even with tread remaining. A tire can require replacement before its warranty expires.
What to look for while you are down there
Inspect for cracks, cuts, bulges and irregular wear. NHTSA also recommends consulting a tire professional about pressure loss, noise or vibration. Do not use the calculator’s warranty result to dismiss damage or a performance change.
Check cold inflation against the applicable tire and vehicle guidance. The tire pressure calculator explains how measured loads and manufacturer tables fit together. If a wheel is removed, use the specified fastener procedure; the lug nut torque guide explains the measurements and rechecks.
DOT date code examples
Week 1 begins on the first Sunday of the year. Warranty months below are approximate five-year anniversaries under Lionshead’s ST radial tire terms:
| Last four digits | Made | Lionshead five-year estimate |
|---|---|---|
| 0109 | 4–10 January 2009 | January 2014 |
| 2419 | Week 24 — June 2019 | June 2024 |
| 3022 | Week 30 — July 2022 | July 2027 |
| 5023 | Week 50 — December 2023 | December 2028 |
0109 is the regulation’s own example from 49 CFR 574.5. The warranty column applies to tires sold under Lionshead’s terms; other suppliers set their own.
What the sizes carry
| Model | Size | Load range | Max load | Max pressure | Warranty runs from | Buy |
|---|---|---|---|---|---|---|
| Westlake ST205/75R15 LRC | ST205/75R15 | Load Range C | 1,820 lb per tire | 50 psi cold | Five years from the manufacturer's date code, not from the date you buy it | Check price(opens in a new tab) |
| Westlake ST205/75R15 LRD | ST205/75R15 | Load Range D | 2,150 lb per tire | 65 psi cold | Five years from the manufacturer's date code, not from the date you buy it | Check price(opens in a new tab) |
| Castle Rock ST205/75R15 LRC | ST205/75R15 | Load Range C | 1,820 lb per tire | 50 psi cold | Five years from the manufacturer's date code, not from the date you buy it | Check price(opens in a new tab) |
| Castle Rock ST225/75R15 LRD | ST225/75R15 | Load Range D | 2,540 lb per tire | 65 psi cold | Five years from the manufacturer's date code, not from the date you buy it | Check price(opens in a new tab) |
| Westlake ST225/75R15 LRE | ST225/75R15 | Load Range E | 2,830 lb per tire | 80 psi cold | Five years from the manufacturer's date code, not from the date you buy it | Check price(opens in a new tab) |
Two things worth reading out of that. The last column is the same for every row — every one of these runs its warranty from the date code. And the Westlake and Castle Rock ST205/75R15 Load Range C publish identical figures: 1,820 lb at 50 psi. Where two lines from one supplier are the same on paper, the date code on the tire you are handed is the thing left to compare.
Where this goes wrong
- Reading the wrong sidewall. The full code may be on the other sidewall. No code visible usually means the marked face is inboard.
- Assuming new stock is new. The commonest and most expensive mistake on this page. The tire was made when it was made.
- Buying up a load range to fix an age problem. A stiffer tire at a higher pressure does not age more slowly. If the tires are old, buy new ones in the rating you actually need — the calculator recommends the smallest that carries your weight for exactly this reason.
- Using the dry weight for the per-tire figure. Axle weights come from a scale with the trailer loaded. The towing payload calculator covers getting those numbers honestly.
The common size, entry load range
Westlake ST205/75R15 LRC
1,820 lb a tire at 50 psi — the rung most single-axle and lighter tandem trailers actually need, rather than the one up.
Same size, one step up
Westlake ST205/75R15 LRD
2,150 lb at 65 psi. Worth it when your per-tire weight is an estimate rather than a scale reading.
The heavier 15 inch
Westlake ST225/75R15 LRE
2,830 lb at 80 psi — check your compressor and gauge reach that before you fit them.
Questions worth answering
How do I read a tire date code?
The final four digits of the DOT Tire Identification Number give the week and year. For example, 2419 means week 24 of 2019. Week 1 starts on the first Sunday of the year under 49 CFR 574.5. Check both sidewalls if you cannot find the complete TIN.
Does the tire warranty run from purchase or from manufacture?
It depends on the supplier. Lionshead's ST radial tire warranty runs five years from the manufacturing date code. Its separate No Excuses guarantee runs twelve months from purchase. Check the policy for your exact tire; the calculator uses Lionshead's five-year term as an estimate, not a universal promise of coverage.
When should I replace RV tires because of age?
Follow the tire and vehicle manufacturers' guidance for your exact application. A warranty expiry is not a replacement interval. Age, condition and use all matter, and a date code cannot establish serviceability. Have damage or changes in tire performance assessed by a tire professional.
What does the warranty actually cover?
Lionshead's five-year policy concerns defects in materials and workmanship, subject to exclusions and claim verification. A crack or bulge does not automatically qualify: inflation, loading, road hazards and other causes matter. Follow the current policy's claim process and notice deadline.
My tire has a three-digit code. What does that mean?
It was made before 2000. The four-digit week-and-year format has been required since then, so a three-digit code means the tire is at least a quarter of a century old. At that point its age is the only fact about it worth knowing.