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Is Tire Grooving Street Legal?

Tires are the most important part of any 4x4 vehicle. Without a good set of off-road tires, even the most high-tech buggy would become ineffective. For this reason, a handful of companies specialize in producing hard-core off-road tires with sticky rubber compounds, aggressive tread patterns, and tire sizes up to 54" tall. For some off-road enthusiasts, though, even these specialty tires aren't good enough. To improve upon an already great product, four-wheelers remove portions of the tire's tread in a process called tire grooving. If done correctly, this will improve carcass flex, mud clearing, traction, and overall off-road performance. The question is, does cutting into a tire like this make them illegal to drive on the street?

Considering that street-legal laws only prohibit modifications and equipment, it is a good sign that most states do not reference tire grooving in their codes or statutes. The seventeen states that do mention tire grooving in their laws are listed below:

California, Kentucky, Nebraska, New Hampshire, and Wisconsin specifically prohibit tire grooving.

Maryland, Virginia, and Washington only allow the grooving of tires that are specifically designed and labeled for grooving. Unfortunately, "regroovable" tires tend to be commercial tires that are of little use to off-roaders.

Alabama, Illinois, Iowa, Kansas, Maine, Michigan, Minnesota, Oklahoma, and Pennsylvania allow tire grooving as long as tires are not grooved below the original tire tread depth. (Tires should never be grooved below their original tire tread depth anyway, even if it is not specifically prohibited.)

In addition to the above listed state laws, there are a couple of federal laws on tire grooving. Section 49-7-A-301-2-30123 of the US Code prohibits the sale of regrooved tires unless authorized by the Secretary and FMVSS Part 569 stipulates that only tires that are designed for regrooving can be regrooved. Tires that have been regrooved are also required to be marked or labeled as such. Luckily, these laws only apply to manufacturers, distributors, and retailers so they should not prevent individuals from grooving their own tires.

Based on this information, tire grooving is prohibited California, Kentucky, Nebraska, New Hampshire, and Wisconsin and it might as well be illegal in Maryland, Virginia, and Washington because most (if not all) popular off-road tires are not labeled for regrooving. The good news is that tire grooving does not appear to be illegal in the remaining 42 states.

Not-illegal is not the same as legal, and for that reason it is important to look at the potential consequences of driving a vehicle equipped with regrooved tires. Just like most street-legal equipment laws, the risks are mainly fix-it tickets and lawsuits.


The probability of getting a fix-it ticket for grooved tires is very rare.
A) Only a trained eye will be able to spot a grooved tire, especially if it was done well.
B) Most police officers don't know what tire grooving is or why it is performed.
C) Most police officers don't know if tire grooving is allowed or not.
D) Police officers are hesitant to write tickets for things they are not sure are unlawful.


A fix-it ticket would be a minor inconvenience as it could either be argued in court or satisfied by replacing the wheels and tires and passing a tech inspection.


The worst possible scenario would be having a tire blow out on the road resulting in a severe accident. Lawyers for any injured party would likely inspect the vehicle for equipment modifications to help build their case against the driver. The solution to this problem is maintaining a solid insurance policy. Anytime modifications are made to a vehicle, the insurance company should be made aware of the change to make sure insurance coverage remains in full effect.

Other Tire Laws

While on the subject of tires there are several other tire related laws to be aware of.


There is a federal law that requires a minimum tire tread depth of 1/16th inch. This law is echoed in many states' laws and California goes so far as requiring 2/16th inch tread depth on front tires.


All states have a catch-all rule that requires all vehicle equipment to be in safe operating condition. Most states even specifically prohibit the use of tires with bulges or exposed cords.


Tires marked as "for racing use only" or "for off-road use only" are illegal for street use.


When it comes to DOT approval, only New Jersey and California have laws requiring tires to be DOT approved. Outside of these two states, it is not illegal to drive on non-DOT approved tires, it is only illegal to sell them (thus eliminating the ability to get them).

Tire grooving is a great way to improve a tire's traction, flexibility, and off-road performance, but it can also make tires very dangerous if the process is not done correctly. One should never groove a tire below the original tire tread depth and it is important to remember that tire grooving will void most tire warranties. recommends that tire grooving only be performed on tires intended for off-road use only.

$300 LIFTLAWS.COM BOUNTY - Anyone that provides us with documentation showing that tire grooving is illegal outside of the states that currently prohibit tire grooving listed above will have $300 donated to the BlueRibbon Coalition in their name.

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