What 393.65C means in plain language
FMCSR 393.65C prohibits operating a commercial motor vehicle with a tire that is flat or has an audible air leak. This is straightforward: if your tire is completely deflated or actively leaking air loudly enough to hear, your truck is not legal to operate on the road.
The rule exists because a flat or severely leaking tire compromises your ability to control the vehicle, increases stopping distance, and can cause a blowout that endangers you and other road users. An audible leak means air is escaping fast enough that an inspector can hear it during a roadside check—it's not a slow pinhole leak that might go unnoticed, but an active problem that will worsen quickly.
If you're cited, it means an inspector found at least one tire on your vehicle in this condition at the moment of inspection. This is not a warning code; it reflects a real safety defect that was present during the stop.
What our enforcement data actually shows
Across our 13 million+ inspection records, 393.65C has generated 245 all-time citations, with 150 citations in the last 12 months and 26 in the last 90 days. The code ranks #1165 of 3,036 FMCSR codes by citation volume—relatively uncommon compared to high-frequency violations, but not rare.
What stands out is the out-of-service (OOS) rate. Our data shows that 183 of 245 citations (74.7%) resulted in an out-of-service order. This is significantly higher than the all-FMCSR average OOS rate of 31.4%. In practical terms: if you get cited for 393.65C, there is roughly a three-in-four chance your truck will be pulled from service on the spot until the tire is repaired or replaced.
The monthly trend over the last 12 months shows fluctuation. October 2025 was the peak month with 27 citations and 20 OOS orders. Recent months (January–April 2026) have seen lower volume, with 8 to 13 citations per month, suggesting this may be seasonal or driven by road conditions.
Who gets cited most
Our inspection records show Texas leads all states in 393.65C citations over the last 180 days, with 48 citations and a 64.6% OOS rate. Illinois follows with 10 citations (70.0% OOS rate), and North Carolina has 5 citations (80.0% OOS rate). New Mexico recorded 3 citations with a 100% OOS rate—every citation in that state led to an out-of-service order—though the sample size is smaller.
The variation in OOS rates across states is notable. New Mexico and North Carolina show rates well above 70%, while Iowa's 33.3% rate is below the national 74.7% average for this code, suggesting inspectors in different regions may have slightly different enforcement thresholds or tire-condition severity varies by geography.
At the carrier level, our data shows fleets such as Julio Cesar Lerma Gonzalez (USDOT 2441559) and Edgardo Lara Martinez (USDOT 4118852) with 3 citations each across our database. Several smaller operators and logistics firms appear with 2 citations. These are not repeat violators at alarming rates, but they do illustrate that the violation occurs across diverse carrier types and sizes.
How severe is this compared to similar codes
Vehicle maintenance violations fall into the same category as 393.65C. Our data allows direct comparison:
- 393.9 (Inoperable Required Lamp): 180,097 all-time citations with a 6.9% OOS rate. This is far more frequent but results in OOS far less often.
- 396.3(a)(1) (Inspection/repair/maintenance—general): 236,919 citations with a 45.3% OOS rate. More common and a higher OOS rate than inoperable lamps, but still well below 393.65C.
- 393.11 (Lighting devices/reflectors): 179,734 citations with a 1.8% OOS rate. Extremely rare to see OOS for this violation.
The 74.7% OOS rate for 393.65C places it among the most likely maintenance violations to result in an immediate out-of-service order. This reflects the safety-critical nature of tire integrity. Inspectors treat this as non-negotiable.
How to avoid it
Tire-related citations often co-occur with other maintenance defects. In the last 90 days, our data shows that 393.65C appeared alongside 396.3A1 (general inspection and repair issues) in 9 shared inspections, and with 393.48A (brake defects) in 3 shared inspections. This pattern suggests that tire problems are part of a broader vehicle-condition issue.
Here are concrete steps to prevent a 393.65C citation:
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Pre-trip tire inspection every single day: Walk around your truck before each shift. Look for visible flat spots, bulges, or obvious damage. Listen for hissing sounds near the wheel wells. If you hear or see anything abnormal, do not operate the vehicle—report it to your dispatcher or maintenance immediately.
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Check tire pressure weekly and after hard use: Low pressure is often the first sign of a slow leak. Carry a tire-pressure gauge and know your manufacturer's recommended PSI for your tires and load. Underinflated tires are more prone to flats and blowouts.
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Inspect tire tread depth: Use the penny test (insert a penny upside-down into the tread; if you see the top of Lincoln's head, tread is too shallow) or carry a tread-depth gauge. Worn tires are more likely to develop leaks or fail.
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Rotate tires on schedule: Ask your maintenance department to rotate tires according to the truck manufacturer's interval. This extends tire life and helps catch developing issues early.
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Report maintenance needs immediately: If you notice any sign of a leak, flat, or tire damage during operation (vibration, noise, pulling to one side), pull over safely and contact dispatch. Do not continue driving; tire failure at highway speed is dangerous and expensive.
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Know your vehicle: Freightliners (64 citations in our data), Fords (36 citations), and Kenworths (25 citations) appear most frequently in 393.65C enforcement. If you drive one of these popular models, be especially diligent—it may simply reflect their prevalence, but consistent attention to tire condition is the best defense regardless of make.
The bottom line: a 74.7% OOS rate means this violation is taken seriously by roadside inspectors. A flat or audibly leaking tire is not borderline—it is a safety defect that will almost certainly take your truck out of service. Daily pre-trip inspection and immediate reporting of any tire abnormality are your strongest defenses.