DOT Tire Tread Depth Requirements
Federal minimum tread depth for commercial truck tires under 49 CFR §393.75, the stricter CVSA out-of-service thresholds, and other tire conditions that will get you placed out of service.
Tires are the second most common vehicle violation category at roadside. The federal standard is 49 CFR §393.75. The CVSA Out-of-Service Criteria set separate, lower thresholds for when a tire is bad enough to stop the truck.
Minimum tread depth
| Position | FMCSR violation (§393.75) | CVSA out-of-service |
|---|---|---|
| Steer (front) tires | Less than 4/32" in any major groove | Less than 2/32" in any major groove |
| All other tires (drive, trailer) | Less than 2/32" in any major groove | Less than 1/32" in any two adjacent major grooves |
Measure in a major tread groove, not on a tread-wear indicator bar, at several points around the tire.
Other tire violations
- Exposed fabric, cord, or belt material through the tread or sidewall (OOS).
- Tread or sidewall separation, bulges, or knots (OOS).
- Flat tire or audible air leak (OOS).
- Underinflation, or a tire that contacts another tire or any part of the vehicle (OOS when they touch).
- Regrooved or recapped tires on the steer axle of a bus (§393.75(d)). Recapped steer tires are allowed on trucks.
- Load exceeds the tire's rated capacity (§393.75(f)).
- Speed-restricted tires used beyond their rating.
Tips for drivers
- Carry a tread-depth gauge and a calibrated tire gauge. Thumping a tire won't detect underinflation.
- Check duals for objects lodged between them and for matching wear.
- Look for irregular wear. It often points to alignment or suspension problems that inspectors will also cite.
DotCheck can analyze a close-up photo of a tire and flag likely tread, sidewall, or inflation issues with the matching CFR section.
FREQUENTLY ASKED QUESTIONS
What is the legal tread depth for a semi truck steer tire?
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49 CFR §393.75 requires at least 4/32 inch of tread depth in every major groove on steer tires.
What tread depth puts a truck tire out of service?
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Under CVSA criteria, a steer tire with less than 2/32 inch in any major groove, or another tire with less than 1/32 inch in two adjacent major grooves, is out of service.
Are recapped tires allowed on a truck's steer axle?
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Recapped or retreaded tires are prohibited on the front wheels of buses, but are not prohibited on the steer axle of trucks or truck tractors under federal rules.
This guide is for general information and pre-inspection preparation only. It is not legal advice. Always check the current text of 49 CFR at ecfr.gov and the current CVSA OOS Criteria.