What 393.67(f) means in plain language
FMCSR 393.67(f) addresses tire defects beyond the minimum tread depth or wear indicators that other tire codes cover. Specifically, you're in violation if your tires show fabric exposed underneath the rubber, bumps or bulges in the sidewall or tread, or cuts deep enough to expose internal structure.
This isn't about how much tread you have left—that's a different code. This is about structural integrity. A bulge means the tire's internal cords are failing. Exposed fabric or deep cuts create a blowout risk, especially at highway speeds or under load. Inspectors look for these defects during roadside checks because a tire failure at 65 mph doesn't just cost you a citation; it can cost you your load, your truck, and potentially lives.
You might see fabric showing through wear, or feel a bump on the sidewall that wasn't there before. Both of those trigger this code.
What our enforcement data actually shows
Across 13 million inspections in our database, 393.67(f) has generated only 11 all-time citations, with zero citations in the last 90 days and zero in the last 12 months. This code ranks #2167 out of 3,036 FMCSR codes by citation volume.
More importantly for you: none of those 11 citations resulted in an out-of-service order. That's a 0.0% OOS rate. By comparison, the all-FMCSR average OOS rate is 31.4%. What this means is that when inspectors find tire defects under this code, they typically issue a citation but don't ground your truck on the spot—you get time to repair before your next inspection cycle.
That said, the low citation volume doesn't mean this violation is harmless. It means most drivers catch these defects during pre-trip or weekly inspections, before an inspector does. The enforcement rarity reflects good compliance across the industry, not lax enforcement.
Who gets cited most
Our inspection records don't break citations for this code down by state; the volume is too small for geographic patterns to emerge meaningfully. However, the carrier data shows that individual owner-operators and small fleets account for the citations in our database. Benjamin Herrera Cano (USDOT 554927) appears with 2 citations; all other carriers in the data have 1 each.
The vehicle makes most often cited are Freightliners (6 citations), followed by Dodge units (2 citations), with single citations across Mack, Peterbilt, Great Dane, and utility trailers. Freightliner's prevalence likely reflects the sheer volume of Freightliners on the road rather than a quality issue with that manufacturer.
How severe is this compared to similar codes
To put this in perspective, 393.67(f) sits in the Vehicle Maintenance category alongside codes like 393.9(a) (Inoperable required lamps) with 660,737 all-time citations and a 15.4% OOS rate, and 396.3(a)(1) (Inspection/repair/maintenance—general) with 236,919 citations and a 45.3% OOS rate.
The low citation count for 393.67(f) makes direct enforcement comparison less useful than behavioral comparison. A code like 393.78 (Windshield condition defective) has 157,894 citations with a 0.3% OOS rate—also seldom resulting in roadside out-of-service. The difference: windshield defects are purely visibility issues. Tire defects are safety-critical structural failures, so they're cited less often because drivers catch them first.
How to avoid it
Before every shift:
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Walk the perimeter of your tires. Run your hand around each sidewall. Feel for bumps, bulges, or soft spots. These signal internal cord failure. If you find one, that tire is coming off before you move the truck.
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Look for exposed cords or fibers. If you can see the fabric or steel belts underneath the rubber, you're at violation threshold. Mark the tire with chalk and get it replaced—don't wait for an inspection.
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Check for cuts longer than 1/8 inch that go deep. A shallow graze is cosmetic. A cut deep enough that you can't easily see the bottom is a defect. If in doubt, use a penlight and inspect closely.
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Pay special attention to Freightliners and trailers with heavy axle loads. Our data shows Freightliners cited most under this code. Load imbalance and underinflation accelerate tire wear and bulging, especially on drive axles and trailer tandems. Check pressure weekly, not just pre-trip.
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Inspect tires after long hauls on rough pavement or debris fields. Road hazards—potholes, debris, metal strips—often cause the cuts and impact damage that show up as defects. After highway stretches with rough road, do a second walk-around.
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Maintain tire pressure to spec. Underinflated tires bulge and wear unevenly. Overinflated tires are fragile. Your door jamb placard specifies the correct cold pressure. Check it weekly with a calibrated gauge, not a gas station dial.
If you catch a defect during pre-trip, repair it before dispatch. If an inspector cites you for 393.67(f), expect a citation but not an immediate out-of-service order based on our data. Still, fix the tire before your next road inspection or you risk escalation.