What 393.65B-F means in plain language
FMCSR 393.65B-F prohibits operating a commercial motor vehicle when any tire is flat or has an audible air leak. This is straightforward: if you can hear air escaping from a tire, or if a tire has lost enough pressure to be visibly flat, your truck is not road-legal under federal rules.
The regulation focuses on tires in a state where they cannot safely support the vehicle's weight or maintain proper contact with the road. A flat tire creates immediate risk of blowout, loss of vehicle control, or sudden failure. An audibly leaking tire is losing pressure in real time and will worsen during your drive.
This violation is cited at roadside inspection when an inspector observes or audibly detects the problem. It is not an out-of-service eligible violation, meaning the inspector will issue a citation but is not required to pull you from service on the spot — though they may recommend repair before continuing.
What our enforcement data actually shows
Across our 13 million+ inspection records, 393.65B-F ranks #1870 of 3,036 FMCSR codes by citation volume. We have recorded 24 citations all-time for this code, with 13 citations in the last 12 months and 1 in the last 90 days.
The out-of-service rate for 393.65B-F is 4.2% — meaning only 1 out of 24 all-time citations resulted in the truck being placed out of service. This is substantially lower than the all-FMCSR average OOS rate of 31.4%. The reason is clear: this violation is not OOS-eligible by regulation, so inspectors cite it but rarely halt the vehicle unless repair is immediately necessary.
Despite low enforcement volume, the trend in recent months shows sporadic activity. In April 2025, we recorded 3 citations; in subsequent months the rate dropped to 1–2 per month, with one out-of-service placement in September 2025.
Who gets cited most
Our inspection records show 393.65B-F citations concentrated in a small number of jurisdictions over the last 180 days. The United States overall had 2 citations with a 0.0% out-of-service rate. California reported 1 citation (0.0% OOS rate), and Florida reported 1 citation (0.0% OOS rate).
The low state-level numbers reflect the overall rarity of this citation type. No single state or region shows a pattern of elevated enforcement, and OOS rates are consistent at zero across all tracked jurisdictions.
Regarding carrier frequency, our data shows fleets such as Tristate Transportation Company LLC (USDOT 4128221) with 2 citations all-time. The remaining citations are distributed across single instances across carriers including Coursey Construction Company Inc, 365 Logistics LLC, and others. This scattered distribution suggests no systemic fleet-wide problem drives 393.65B-F citations.
How severe is this compared to similar codes
Within the vehicle maintenance category, 393.65B-F sits well below the citation volume and OOS enforcement intensity of related codes.
For comparison, FMCSR 393.9(a) (Inoperable required lamps) has generated 660,737 citations with a 15.4% OOS rate. Another peer code, 396.3(a)(1) (Inspection/repair/maintenance — general), shows 236,919 citations with a 45.3% OOS rate. A third example, 393.11 (Lighting devices/reflectors), has 179,734 citations with a 1.8% OOS rate.
The stark difference in volume underscores that flat or audibly leaking tires, while serious, are caught less frequently than lighting and general maintenance defects. The 4.2% OOS rate for 393.65B-F is also notably lower than the 45.3% rate for broader maintenance violations, reflecting the regulation's non-OOS status and the relative ease of tire replacement.
How to avoid it
Flat and audibly leaking tires are nearly always preventable with disciplined pre-trip inspection and attentive driving.
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Conduct a thorough pre-trip tire inspection every time you move the vehicle. Walk around the entire truck and trailer. Look for visible flattening, bulges, uneven wear, or debris embedded in tread. Squat down and listen — lean in close to each tire and listen for air leaks. If you hear a hiss, do not drive.
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Check tire pressure with a calibrated gauge. Do not rely on visual assessment alone. Our data shows Freightliner (7 citations), Ram (5 citations), and Utility (3 citations) vehicles represent the top makes cited for this violation. These vehicles have different tire specifications and inflation requirements. Know your vehicle's placard pressure and confirm each tire meets it before departure.
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Address any suspicious sound or appearance immediately. If during your drive you hear a tire hissing or notice vibration or unusual handling, pull over safely at the next opportunity and inspect. Do not assume it will hold until your next stop.
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Maintain a tire plug kit and portable compressor in your truck. If you develop a slow leak on the road and confirm it is not audible and the tire holds pressure with a top-up, you have documentation of your good-faith effort to repair. This does not excuse operating with an active leak, but it shows diligence.
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Rotate and balance tires per manufacturer spec. Uneven wear can lead to pressure loss. Our co-occurring violation data shows that drivers cited for 393.65B-F also occasionally carry citations for wheel/rim defects (393.205C-WR) and other tire pressure violations (393.75A3-TAOL), suggesting that systemic tire maintenance gaps are the root cause. Regular rotation and balancing prevent these cascading issues.
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Replace tires before they age out. Tires degrade over time even if not driven. Follow your carrier's or the DOT's age guidelines (typically 10 years from manufacture). Aging tires are more prone to leaks and sudden failure.