Your tires are one of the most critical pieces of equipment on your vehicle, along with things like brakes and headlights. Tires connect your vehicle to the surface on which you are driving, whether that be the street or an off-road trail. They provide traction, which gives you control over where the vehicle is going.
If you have a vehicle that you use both on- and off-road, you may be wondering if you can use off-road tires on the road and highway.
There are several considerations when assessing if you can use off-road tires on-road and on the highway. The first and most important is the legal consideration, not all off-road tires are street legal. You will have to check that the specifications of the tires meet your local state guidelines for street tires. If they do not meet these guidelines, then they are not legal for use on public roadways.
The Department of Transportation in the United States has several regulations regarding tires sold, and you may see phrases such as DOT-legal and DOT-approved, neither of these guarantees that the tires are legal for street use in your area. DOT is a federal bureau, and while tires may meet DOT guidelines, they may not fit your local state’s laws regarding tires approved for street use and, as such, would not be “street legal.”
There are other considerations around safety and comfort as well as wear and tear surrounding the use of off-road tires on public roads and highways, which we will dig deeper into later in this article.
Are Your Off-Road Tires Legal?
First, let’s discuss the legality issues a little more in-depth so that you will have a better understanding of tire regulations in the United States.
Federal and state laws are both applicable when assessing the legality of tires. As previously mentioned, DOT is the national board tasked with setting the U.S. guidelines regarding motor vehicles and automotive equipment sold in the United States.
At a minimum, your tires must meet DOT standards if you want to use them on a public roadway. These tires will have the marking to indicate that they are DOT-compliant (sometimes incorrectly stated as “DOT-approved” more info on DOT terminology below).
Your local state may have additional guidelines that tires must meet to be considered street legal in your area. If this is the case, the tires you choose must meet both sets of rules. Always check your local state laws with regards to what is considered “street legal.”
In general, local officials are going to be the authorities you have to deal with for these matters, as the FBI is not usually going to be pulling you over to inspect your vehicle for DOT-compliance.
There are a few more things you need to know regarding DOT terminology used in the auto industry.
DOT-approved is a term that you will often see but is entirely incorrect. The Department of Transportation does not approve products for use in the United States. Instead, they set guidelines that products must adhere to for these products to be sold for use on public roads and highways.
As such, products should be referred to as “DOT-compliant” if they meet these standards and are labeled to indicate so. Thus, DOT-approved really means DOT-compliant.
Another term you might see is DOT-legal. Despite seeming more stringent because of the use of the word “legal,” it is actually the opposite. DOT-legal, while not an official term endorsed by the Department of Transportation, generally means that all the DOT regulations have been met but, the proper markings are not placed on the product. Thus, the use of this term implies less stringency on the product.
Remember that being DOT-compliant does not necessarily mean that you can use those tires on public roads in your state.
Are Your Off-Road Tires Safe?
Safety should probably trump legality, but in this instance, it is probably safe to assume that if the tires are legal, then they are safe.
The safety of a tire depends on the conditions in which it will be used. DOT-compliant tires are generally safe. However, the climate and terrain of each state can differ wildly, which is why some states have additional requirements for tires that are to be used on public roads and highways.
If your off-road tires are DOT- and state law compliant, then you can be assured that they are safe for you to use on the road and highway.
Off-Road Tire Wear & Tear on the Road
You might think that because off-road tires are built for use on rough and variable terrain that they could easily withstand the rigors of flat roads and highways. However, this is not the case.
Off-road driving is done at relatively low speeds, through mud, over rocks and boulders, and other hazards. Because of this, they are constructed with bigger treads, which gives them improved grip in these harsh conditions and clears away the gravel, mud, and other debris.
The tires are also reinforced, giving them increased abrasion and puncture resistance needed for protection against the dangers of off-road trails.
In contrast, street tires are built for flat humanmade surfaces, which allow for high speeds. Thus, they are usually constructed with smaller treads that can withstand higher rates of speed.
The bigger treads on off-road tires, especially mud-terrain tires, will wear much quicker on flat surfaces at high rates of speed, i.e., on roads and highways. If you do a lot of street driving with mud-terrain tires, you may get as little as 20,000 miles out of your tires before you have to replace these costly beasts.
All-terrain tires are another off-roading option. As the name implies, they try to strike a balance between providing on- and off-road performance.
For people who use their vehicle for a mix of street driving and off-roading but don’t want to swap out tires, all-terrains are your best bet. They cannot handle conditions as extreme as mud-terrain tires, but they can handle highway speeds without the wear and tear that you will get with mud-terrain tires.
Do Off-Road Tires Provide a Comfortable Ride On-Road?
Mud-terrain tires used for off-roading are not built to provide a comfortable ride on the road. All-terrain tires can usually rival regular street tires for comfort and noise.
Because all-terrain tires generally function as well as other street tires when it comes to comfort, this section will look at mud-terrain tires and their use on roads and highways.
Mud-terrain tires are reinforced, which gives a rougher ride. They also often have lugs on their edge meant to grip rocks or boulders that are rubbing up against the side of the tire. On a roadway at slow speeds (under 15-20mph), you can usually feel these lugs hitting the road, which again decreases the comfort of the ride they provide in street conditions.
Mud-terrain tires are not likely to make the ride unbearable, but they will undoubtedly provide a rougher ride than street tires.
Another consideration is noise, street tires are designed to provide a quiet ride, or as quiet as possible anyways.
Mud-terrain tires are not designed with noise in mind. These tires will be significantly louder than your average street tire. The level of noise will vary depending on the tire you choose, but they will be louder than their street counterparts.
This added noise can be annoying for those riding inside the cab, especially on longer journeys. Road noise can also contribute to driver fatigue if long-distance driving is a concern.
The noise can also be a nuisance to those outside the vehicle. This is less of concern on the highway, but on public roads, especially in more residential areas, this may annoy the neighborhood and cause unwanted tension with your neighbors.
Any tires that are compliant with your local state laws and DOT regulations are legal for street use. However, just because you can use them on the road doesn’t mean you should. The high speeds of road driving can quickly wear out mud-terrain tires, and these tires do not provide a comfortable or quiet ride.
If you do a mix of off-roading and street driving, consider getting all-terrain tires, or have two sets of tires, one set for off-roading and on for the streets.