FMCSR 393.75A: Tire General Defects – Driver Q&A

Yes — and the odds are extremely high. Across all-time inspection records, 393.75A carries a 90.0% out-of-service rate, meaning 11,431 of the 12,699 documented citations resulted in the vehicle being parked on the spot. That is nearly three times the all-FMCSR average OOS rate of 31.4%. If an inspector finds a tire that fails the minimum tread depth standard or shows a disqualifying defect, plan on not moving until the tire is replaced or the violation is corrected. Do not assume your rig will roll away just because the code is marked OOS-eligible. The data says otherwise.

A 393.75A citation carries a CSA severity weight of 6. That base score is then multiplied depending on how recently the inspection occurred: violations within the last 6 months receive a 3× time-weight multiplier, violations between 6 and 12 months receive a 2× multiplier, and violations older than 12 months carry a 1× multiplier. So a fresh 393.75A hit scores 18 weighted points in the Vehicle Maintenance BASIC. The severity weight of 6 puts this squarely in the mid-range tier — not the highest possible, but high enough to move a carrier's BASIC percentile noticeably, especially if multiple drivers on the same fleet accumulate citations. Our inspection records show 8,378 citations in just the last 12 months, so inspectors are actively writing this code.

Follow these steps immediately:

1. Document everything on the spot. Photograph all four tires (or all axle positions) before any repairs, so you have pre-repair evidence for a DataQs challenge if needed.
2. Fix the defect before moving. With a 90.0% OOS rate, there is a high probability you are already parked. Do not attempt to drive to a shop unless the inspector clears you.
3. Check the rest of the truck. Our inspection records show 393.75A frequently appears alongside 393.9 (inoperable required lamp, 293 shared inspections in the last 90 days), 393.9TS (inoperative turn signal, 165 shared inspections), and 393.78 (windshield condition, 149 shared inspections). Fix every item on that inspection report — inspectors who find one defect often find several.
4. Notify your fleet safety manager so the citation is logged and the CSA severity weight of 6 is factored into your BASIC projections.

Yes — it stands out sharply even among Vehicle Maintenance violations. The all-FMCSR average OOS rate is 31.4%, and most peer codes in the same category sit well below 393.75A's 90.0% rate. For comparison, our inspection records show 393.9 (inoperable required lamp) has a 6.9% OOS rate across 180,097 citations, and 393.78 (windshield defective) sits at just 0.3% across 157,894 citations. At 90.0%, a tire general defect finding almost always means the vehicle is parked. The code also ranks #193 out of 3,036 FMCSR codes by citation volume, so it is both common and severe — a combination that puts fleets at real BASIC percentile risk.

Yes, you can submit a DataQs Request for Data Review (RDR), but the path to success depends on your evidence. Because 393.75A is an equipment finding — a physical condition of the tire — the most viable challenges are cases where the inspector's determination was factually incorrect (e.g., tread depth was actually compliant and you have documentation or photos to prove it) or where the violation was recorded against the wrong vehicle or driver. Pure disagreement with the inspector's judgment, without supporting evidence, rarely succeeds. If the tire was genuinely defective and you have no contradicting evidence, the record will almost certainly stand. Start the process at the FMCSA DataQs portal and attach every photograph and repair receipt you collected at the scene.

Texas, North Carolina, and Illinois lead all states in 393.75A enforcement volume over the last 180 days. Texas logged 1,682 citations with an 88.8% OOS rate; North Carolina followed with 1,420 citations and an even higher 98.2% OOS rate — meaning inspectors in NC almost universally park vehicles when they find this defect. Illinois recorded 462 citations at a 78.8% OOS rate. New Mexico added another 368 citations at an 89.1% OOS rate. If your lanes run through Texas or the Carolinas, tire condition should be a pre-trip priority, not an afterthought. The 8,378 citations logged in just the last 12 months confirm this code is actively enforced nationwide.

It cannot wait. The 90.0% all-time OOS rate means that in nine out of ten documented cases, the vehicle was placed out of service immediately — the defect was never treated as a deferred maintenance item by the inspector. Our inspection records show 1,836 citations in just the last 90 days, and the monthly trend shows consistent volume: October 2025 alone produced 845 citations with 769 OOS placements. A tire carrying a general defect is an active enforcement target every time the truck passes through a port of entry or fixed scale. Repair the tire before the next dispatch, not at the next scheduled PM interval.

It follows both — but in different BASIC categories. Under FMCSA's CSA methodology, a 393.75A citation is recorded in the Vehicle Maintenance BASIC. That BASIC is attributed primarily to the carrier, because maintaining equipment is the carrier's legal responsibility. However, the citation does appear on the driver's inspection history and can affect their individual safety record and employability. Our inspection records show that major carriers accumulate this code in volume — Swift Transportation leads all-time with 68 citations, followed by Federal Express Corporation with 59 and both US Xpress and Schneider National at 54 each. That pattern reflects a fleet-level equipment issue, not individual driver behavior, which is exactly how CSA is designed to separate driver accountability from carrier accountability.