DOT Tire Regulations & Standards: All You Need to Know | Hale Trailer Brake & Wheel, Inc.
The Federal Motor Carrier Safety Administration (FMCSA) of the US Department of Transportation (DOT) maintains sets for numerous vehicle regulations; as a motor carrier or driver, it is your responsibility to know DOT tire regulations and conduct regular checks. For a complete list of tire restrictions, refer to section 393.75 of the FMCSA regulations.
Importance of Checking Tires
Tires are an important part of a commercial truck and one of the easiest to maintain. They give you a better grip on the road and allow you to stop faster, as well as extending the life of the truck, saving you time and money on repairs or purchases.
Commercial Truck and Trailer Tire Regulations
Tire inspection and maintenance extends beyond a quick check before hitting the road; according to the FMSCA and DOT tire regulations, there are specific codes in the Code of Federal Regulations that address tires, including Section 393.75 in the eCFR.
1. Tread Depth
Measurements are to be taken at a “major tread groove,” but there are differing interpretations of what that means. DOT steer tire regulations state that the depth must be at least 4/32 of an inch, while CVSA regulations have slightly different measurements that could result in a vehicle being recalled.
2. Inflation Pressure and Flat Tires
Following inflation pressure guidelines can help prevent flat tires in the future, as heat causes tire air pressure to rise, resulting in inaccurate readings and under-inflated tires on the road.
3. Exposed Belt Material
If a tire has body ply or belt material exposed through the tread or sidewall, is flat or has an audible leak, or has a cut to the extent that the ply and belt material is exposed, the vehicle is inoperable.
How to Interpret a CSA Tire Score
Vehicle maintenance violations stay on a fleet’s record for 24 months and can affect a driver’s score. Information is gathered from roadside inspections to develop scores, which are weighted based on the types of violations found.
How to Decide Which Tires You Should Buy
Different types and sizes of trailers have different requirements, so if you’re looking for commercial trailers for rent or purchase, you’ll want to think about the tires as well.
Weather and Tire Choice
Tires are marked with the maximum weight they can carry, and a vehicle should not operate if its weight exceeds that listed on the tires, according to DOT tire regulations. Some conditions to consider are: Will there be snow and ice?
Where to Rent DOT-Compliant Commercial Trailers
Hale Trailer Brake examines some of the unique requirements of freight and transportation, as well as how this affects your trailer selection.
What is the minimum tread depth for front tires on a semi?
Tread groove pattern depths on major tread grooves on front wheels must be at least 4/32 of an inch, while other wheels must have a depth of at least 2/32 of an inch.
What is the minimum tread for front tires?
When a tire’s tread wears down to the legal limit of 2/32 inch, US law requires it to have visible Tread Wear Indicator bars running from one side of the tread design to the other.
What should the tire tread depth be on a semi truck?
Semi trailer tires must have a tread depth of at least 2/32u201d according to the US Department of Transportation.
How many 32nds is a new semi tire?
Tire tread depth is measured in 32nds of an inch in the United States; new tires typically have 10/32u201d or 11/32u201d tread depths, with some truck, SUV, and winter tires having deeper tread depths than others.
How much tread is too little for tires?
When is Tread Depth Too Low? The legal minimum tread depth is 2/32 of an inch. This does not mean that tires with 3/32 left of tread are unsafe; it simply means that you will fail your state safety inspection.
Do steer tires have to match?
If a good match for the higher tread steer cannot be found, it should be pulled and used as a matching spare for someone else’s truck after your truck receives a matched pair of steers. Mismatched steers wear poorly and can cause front end vibration.
How long can you drive on a tire with tread showing?
In such situations, the only safe distance is the distance you’ll drive to get to the nearest tire shop for a replacement; any tire with exposed wires should last no more than 87 to 94 miles at most, though it’s difficult to be precise.
What happens when tire tread is low?
Low tread tires are more susceptible to punctures, which can result in sudden blowouts; worn tires are more likely to lose air pressure, which affects a car’s fuel economy, braking, and steering; and low pressure is a major cause of tire blowouts, which can result in a vehicle losing control.
How many miles is 1/32 of tread?
The tread on a new set of tires will wear down about 1/32 inch for every 5,000 to 8,500 miles of normal driving, depending on the tread compound, so a new set of tires will last 40,000 to 70,000 miles on average.
What is the minimum tread depth for all tires other than steer tires?
All other tires (drive tires, trailer tires, etc.) must have at least 2/32-inch tread depth in every major groove, while the front tires (steer tires) must have at least 4/32-inch tread depth in every major groove.
Can you plug a steer tire on a semi truck?
Although it is not illegal to repair a tire on the steer axle of a commercial motor vehicle, it is illegal to operate a tire on the steer axle of any commercial motor vehicle if a section repair has been installed. Despite this, some fleets have decided to limit or prohibit repairing a tire on the front axle of a truck.
What does 3/32 tire tread mean?
6/32″ or higher: Your tread depth is adequate. 5/32″: If snow-covered roads are a concern, you should consider replacing your tires. 3/32″: It’s time to start looking for new tires; they’re nearly worn out. 2/32″ or lower: Your tires are legally bald, and it’s time to replace them.
What is a good tire tread depth?
The tire tread depth gauge measures in 32nds of an inch; a good tire tread depth is 6/32 or deeper; if the depth is 4/32 or less, you should consider replacing your tires; and 2/32 or less means you should replace your tires as soon as possible.
Is 9/32 A good tire tread depth?
The tread depth on used tires can range from 2/32u201d to 90%, but the average is 6-8/32u201d. Tires in good condition should have a minimum of 6/32u201d, or 4/32u201d if the tire is 13-14u201d. The legal minimum tread depth is 2/32u201d, but driving becomes dangerous with such a tread.