What 393.75E means in plain language
FMCSR 393.75E prohibits the use of regrooved tires on the front axle of a truck or truck-tractor. A regrooved tire is one where the tread has been artificially deepened or restored after the tire was originally manufactured — essentially cutting new grooves into a worn tire to make it look and perform like a newer one.
The regulation is straightforward: front tires must be original-tread tires or new tires with factory tread. Regrooved tires are not permitted in the front position because the structural integrity of a regrooved tire—especially under the stress of steering and braking—cannot be guaranteed to match that of an original tire. The front axle carries critical steering and braking responsibility, making tire integrity there especially important.
If an inspector finds a regrooved tire mounted on your truck's front axle during a roadside inspection, you will receive a citation for 393.75E. This is a maintenance violation, not a safety-critical defect that automatically pulls your vehicle out of service.
What our enforcement data actually shows
Across our 13 million+ inspection records, 393.75E is an uncommon violation. Our data shows 8 citations for this code all-time, with 4 citations in the last 12 months and 2 citations in the last 90 days. This ranks 393.75E as #2269 out of 3,036 FMCSR codes by citation volume—a relatively rare finding.
Of the 8 all-time citations, only 1 was placed out of service, giving 393.75E a 12.5% out-of-service rate. This is significantly lower than the all-FMCSR average OOS rate of 31.4%, reflecting the fact that a regrooved front tire is a maintenance defect rather than an immediate safety shutdown. Most drivers cited for this violation are allowed to continue under a repair order; the vehicle is not deemed unfit to operate.
The rarity of this citation suggests that most carriers and drivers are complying with this requirement, or that inspectors encounter regrooved tires on non-front axles (where the rule does not apply) more often than on steered axles.
Who gets cited most
Our inspection records show that in the last 180 days, Texas recorded 2 citations for 393.75E with a 0.0% out-of-service rate. This is the only state in our top-states list for this violation, reflecting both its infrequency nationally and its concentration in high-volume inspection corridors.
Looking at all-time data, our records show fleets such as NGL Transportation Inc (USDOT 1575579) and Johnny M Bullock (USDOT 2511907) each with 2 citations for 393.75E. CNC Logistics S de RL de CV (USDOT 2726203) also appears with 2 citations. These carriers are not outliers in any meaningful way; the distribution across carriers is flat, indicating that this violation occurs sporadically across the industry rather than being concentrated among a particular fleet or operation type.
How severe is this compared to similar codes
393.75E sits within the vehicle maintenance category alongside several far more frequently cited codes. For context:
- 393.9(a) — Inoperable required lamps has logged 660,737 citations with a 15.4% OOS rate. Lighting violations are orders of magnitude more common than regrooved tires.
- 396.3(a)(1) — Inspection/repair/maintenance (general) shows 236,919 citations with a 45.3% OOS rate, meaning maintenance defects in this broader category are cited much more often and with a much higher likelihood of roadside removal.
- 393.78 — Windshield condition defective accounts for 157,894 citations with a 0.3% OOS rate, making it similarly low-enforcement but far more prevalent than regrooved front tires.
The rarity of 393.75E citations combined with its low OOS rate suggests inspectors view this violation as a compliance issue to be documented and corrected, rather than as a severe safety defect.
How to avoid it
Preventing a 393.75E citation requires a simple but often overlooked pre-trip inspection habit:
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Inspect front tire sidewalls and tread carefully during your pre-trip. Look for evidence of re-cutting or artificial deepening of the tread grooves. A regrooved tire will show inconsistent, sharp-edged grooves that appear freshly cut, sometimes with visible feathering or uneven wear patterns. Compare the front tires visually to the rear tires; regrooved front tires often look notably different from original or factory-new tires.
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Do not mount regrooved tires on the front axle under any circumstance. If your fleet's maintenance or tire-buying practices have included regrooved tires as a cost-saving measure, reserve them only for non-steer (rear) axle positions. Front axles must use original-tread or new tires only.
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Know your tire sourcing. If you operate your own truck, ask your tire supplier explicitly whether tires being mounted are original, new, or regrooved. Request new or original tires for the front axle. If you drive a fleet vehicle, confirm with your maintenance department that front tires are never sourced from regrooved inventory.
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Watch for co-occurring defects. Our inspection data shows that 393.75E sometimes appears alongside other maintenance findings like tire tread separation (393.75A2) and insufficient tread depth on other axles (393.75C). If you discover worn or separated tread on any tire, conduct a full tire audit on your vehicle—the presence of one tire defect often signals others.
This violation is rare, manageable, and entirely preventable through attentive pre-trip inspection and responsible tire sourcing practices.