Properly maintained commercial truck tires aren’t just a matter of safety and fuel economy (although that should be enough reason for any owner/operator or fleet manager); it’s a matter of federal regulation. The Federal Motor Carrier Safety Administration (FMCSA) has a number of regulations for commercial tires. If you are found to be falling short of these regulations, you may face citations or even have your truck placed out of service. To avoid these consequences, it’s important to be thorough when conducting pre-trip tire inspections and to repair tire issues in a timely manner.
Key FMCSA Regulations
The first step is to be familiar with FMCSA regulations on commercial truck tires. The key rules are found in section 393.75. This section states that no motor vehicle should be operated on a tire that:
- Has ply or belt material exposed through the tread or sidewall
- Has any tread or sidewall separation
- Is flat or has an audible leak
- Has a cut to the extent that the ply or belt material is exposed
All of these rules refer to major tire problems that would pose a safety hazard not only to you the driver, but to other people on the road. Regardless of regulations, you wouldn’t want to drive with any of these issues. To be extra sure you aren’t violating FMCSA regulations, make sure that you check your commercial tires before each trip for leaks or cuts, and do not drive on a flat tire for any longer than is necessary to pull over safely.
Tire Tread Regulations
The FMCSA also outlines what constitutes acceptable tire wear. All tires must have tread that is at least 2/32nds of an inch deep. For the front tires, the tread groove pattern needs to be at least 4/32nds of an inch deep. Inspectors will measure a major groove, not including the decoupling groove on the tire’s shoulder. They won’t measure where there are any tie bars, humps, fillets, or stone ejectors. If any spot on your tire has a groove less than the required depth, you can potentially receive a citation.
You may hear confusion about FMCSA regulations on regrooved, retreaded, and recapped tires. The rules state that buses cannot use regrooved, retreaded, or recapped tires on the front wheels. Trucks, however, are allowed to use these tires. However, the load-carrying capacity must be under 4,920 pounds (2,232 kg).
The FMCSA specifies that trucks (and other vehicles, for that matter) cannot operate with tires inflated to under the pressure specified for the load they are carrying. An inspector will measure for cold inflation, and if the truck has been running, they’ll use a formula to correct for any increase in the pressure from heat.
If you want to read the FMCSA regulations for yourself, including details on tire loading restrictions, you can find them on the FMCSA website.