Owner decision guide
Trailer tire pressure, load and age checks
Trailer tires operate near high loads and can look usable while aged or underinflated. Set cold pressure according to the trailer/tire requirements, verify load capacity and inspect date codes, cracking and impact damage. Before acting, check Cold pressure and load range, DOT date code and sidewall cracking, Loaded axle weight versus tire capacity. Record the exact condition, since temperature, speed, load and warning status all change the diagnosis. The sections below break this down further: pressure is not a comfort setting, age matters more than tread, sun, storage and load, speed ratings. This is rated routine risk: Do not tow with a bulge, exposed cord, rapid leak, severe cracking, overload or a hot bearing/tire assembly. 4 related questions are answered separately below. Reviewed under this site's evidence-first standard, sourced to NHTSA vehicle and recall guidance, with related towing and trailering guides linked at the end.
Evidence first
Trailer tires fail differently from vehicle tires. They typically age out before they wear out, because trailers sit parked for long periods, carry heavy static loads and often see little annual mileage.
Underinflation and age are the two dominant causes of trailer tire failure, and both are entirely preventable.
Pressure is not a comfort setting
Trailer tires are usually run at or near their maximum stated cold pressure, because they need their full rated load capacity.
The correct figure comes from the trailer's tire placard, not from what feels right and not from the vehicle's placard. Check cold, before driving, not after, because heat raises indicated pressure and hides an underinflated tire.
Age matters more than tread
A trailer tire with abundant tread can still be unsafe.
- Read the DOT date code on the sidewall: the last four digits are week and year of manufacture
- Many trailer-tire manufacturers advise replacement at a set age regardless of tread
- Sidewall cracking, crazing and weathering are age indicators
- Flat spots or a set from long static parking are a warning sign
- A tire that has been run underinflated may have internal damage that is not visible
Sun, storage and load
Ultraviolet exposure degrades sidewall rubber, so a trailer stored outdoors ages its tires faster. Covers help.
Long static parking on a heavily loaded trailer stresses one part of each tire continuously. Where practical, move the trailer periodically or reduce load during storage.
Speed ratings
Many special-trailer tires carry a lower speed rating than passenger tires. Exceeding it builds heat that the construction is not designed to shed.
Check the rating on the sidewall and treat it as a limit, not a suggestion: trailer tire failures at highway speed frequently damage the trailer body as well as leaving you stranded.
What to check before acting
| # | Check | Why it matters |
|---|---|---|
| 01 | Cold pressure and load range | Record the exact condition; differences in temperature, speed, load and warning status change the diagnosis. |
| 02 | DOT date code and sidewall cracking | Record the exact condition; differences in temperature, speed, load and warning status change the diagnosis. |
| 03 | Loaded axle weight versus tire capacity | Record the exact condition; differences in temperature, speed, load and warning status change the diagnosis. |
Record the exact condition; differences in temperature, speed, load and warning status change the diagnosis.
Record the exact condition; differences in temperature, speed, load and warning status change the diagnosis.
Record the exact condition; differences in temperature, speed, load and warning status change the diagnosis.
Safe sequence
What to do next
| Step | Action |
|---|---|
| 1 | Measure pressure before travel |
| 2 | Inspect inner and outer sidewalls plus the spare |
| 3 | Replace damaged or aged tires according to manufacturer guidance |
- 1
Measure pressure before travel
- 2
Inspect inner and outer sidewalls plus the spare
- 3
Replace damaged or aged tires according to manufacturer guidance
Avoid making it worse
What not to do
- Do not judge condition only by tread depth
- Do not mix incompatible load ranges casually
Do not tow with a bulge, exposed cord, rapid leak, severe cracking, overload or a hot bearing/tire assembly.
Source and scope
Common questions
How often should trailer tires be replaced?
Many trailer-tire manufacturers advise replacement at a set age regardless of remaining tread, because these tires age out before they wear out. Check the DOT date code and the manufacturer's guidance.
What pressure should trailer tires run?
Use the figure on the trailer's own tire placard, checked cold before driving. Trailer tires typically run at or near maximum stated pressure because they need full rated load capacity.
How do I read the tire date code?
The last four digits of the DOT code on the sidewall give the week and year of manufacture: for example, 2419 means the 24th week of 2019.
Do trailer tires have a lower speed rating?
Many special-trailer tires do. Check the sidewall and treat the rating as a hard limit, since exceeding it builds heat the construction is not designed to shed.