Start with all of the tires, including the spare

A trailer that travels only a few weekends a year can accumulate little tread wear while its tires continue to age.

  • Check every road tire and the spare rather than reading the newest-looking tire and assuming the set matches.
  • Find the full DOT Tire Identification Number; the complete code may appear on only one sidewall.
  • Read the final four digits as production week and year on modern tires.
  • Record each tire's date code so a mismatched replacement or older spare is easy to spot.
  • Compare the tire size, service type, load information, and inflation requirements with the trailer and tire manufacturer specifications.

The last four digits tell you when the tire was made, not whether it is safe today

A code ending in 1724 indicates the tire was manufactured in the 17th week of 2024. That number is useful because trailer tires can spend years exposed to heat, sunlight, storage loads, and long periods of inactivity even when the tread still looks deep.

NHTSA notes that tires become more prone to failure as they age and that vehicle and tire manufacturers may publish age-based replacement recommendations. Those recommendations are not identical, so use the trailer maker, tire maker, and vehicle documentation instead of turning one internet age limit into a universal rule.

What the date code can and cannot tell you

Recent date code, good condition
A tire that is within manufacturer guidance and also passes pressure and visual checks

Age does not cancel the need to inspect for impact damage, punctures, uneven wear, overload history, or chronic pressure loss.

Older tire with deep tread
A tire that needs an age-and-condition decision rather than a tread-depth decision

Consult the tire and trailer manufacturer's inspection and replacement guidance. Low mileage does not stop rubber from aging.

Unknown age or unreadable TIN
A used trailer, painted sidewall, or tire where the full identification number is hard to locate

Check the opposite sidewall and ask a tire professional to identify the code before a long trip or replacement decision.

Turn the date-code check into a pre-tow inspection

  1. 01
    Check cold inflation pressure

    Use the trailer and tire manufacturer's specified cold pressure and load guidance. Do not lower pressure simply because the trailer is lightly loaded unless the manufacturer provides that procedure.

  2. 02
    Inspect the tread and sidewalls

    Look for cracking, bulges, cuts, exposed cords, objects, irregular wear, or signs the tire has been run underinflated.

  3. 03
    Check the spare and wheel hardware

    A spare that has never touched pavement can still age. Verify its pressure, mounting condition, and that the tools needed to use it are actually on the trailer.

  4. 04
    Resolve doubts before Interstate speed

    A long highway tow adds sustained heat and load. Have questionable tires inspected before the trip instead of using the first hour of towing as the test.

Safety check

Do not use a date code as permission to ignore damage

A newer tire with a sidewall bulge, deep cut, exposed cord, repeated pressure loss, severe cracking, or overload damage can require removal from service regardless of its manufacture date. Tire age is one inspection input, not a warranty that the tire is roadworthy.