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What are semitruck fenders, and how do they work?

If you’re a truck or fleet owner, you know the importance of maintaining your trucks. Without preventative maintenance, your trucks may break, resulting in a costly repair. A crucial part of maintenance is regularly replacing certain components and outfitting your truck with the best, high-quality parts.

Semitruck fenders are an important part of your cab. Ensuring your truck has the right fenders can help preserve the look of your cab and limit preventable damage. Trucks encounter a lot on the road, and fenders help protect them. Know your fender options before buying to ensure that you’re getting the best parts possible.

What are semitruck fenders? 

Semitruck fenders are wheel coverings intended to keep dirt and debris picked up by your tires from hitting your cab. Fenders are made of various materials that offer different levels of wheel coverage. The right fenders can help preserve the look of your cab, prevent damage to your trailer and elevate the exterior look of your truck.

Semitruck fender options 

Many fender options are available for your semi truck. Becoming familiar with their functions, pros and cons will help you decide which is best for your truck.

Full fenders

Full fenders are an option for the rear or drive axles on your truck. A full fender covers both drive axles, providing coverage for both tires with one fender. This provides maximum protection for your rear axles and is the most effective way to limit damage on the road.

Full fenders are a bit more expensive and can make it harder to access parts of your truck. For example, it’s harder to check tires covered by a fender — especially a full one that dips between them. Owner-operators may find it worth it, though, for the protection it provides.

Front fenders

Front fenders, as suggested by the name, cover the tires on the front axle or steering axle. Unlike rear fenders, front fenders may be built into the cab, though on some models they’re separate, removable components. They should only be used on the front, though. They’re designed to be situated away from the tire and won’t provide as much protection as rear fenders. 

Half fenders

Half fenders only cover half of a tire, offering half the protection of full fenders. They also go over one rear or drive axle to limit the number of rocks and debris sprayed by tires. Half-tandem fenders will arch over one wheel, and a flat top may extend to the second tire.

Because they cover less of the tire, they don’t protect you or other drivers as well, but there are benefits. For instance, half fenders are cheaper than full fenders and can make tires more accessible. They’re typically preferred for trucks that pull low-sitting trailers or don’t need much spray protection.

Quarter fenders

Quarter fenders cover a quarter of a tire, blocking a limited amount of debris spray. They offer only half the protection of half fenders, and just a fraction of what’s provided by full fenders.

These fenders are the most cost-efficient, simple solution for trucks that don’t need much protection.  If your truck isn’t heavily used or doesn’t make many long journeys, they may be right for you. 

Single axle

Many trucks have dual-drive axles, but some lighter-load trucks will only have a single axle. These types of trucks will not be able to use a tandem fender, so they will need a single-axle fender. These fenders are similar to full fenders but only protect one tire. They will arch over the tire, giving near complete protection from debris spray.

These axles can also be used on dual-axle trucks in place of a full fender. In this case, both axles would have a single-axle fender, so there would be one fender per tire. This may be a more cost-efficient solution for a dual-axle truck but will not provide quite as much protection as a full fender.

How do semitruck fenders work?

Anyone who’s ever driven a semitruck or seen one on the road knows their tires can pick up a lot of debris. Trucks are so large and heavy that they can wear on the road, causing debris to spray out from the tires. And in rainy weather, their tires can kick up a lot of water. Debris spray can cause damage to your truck and other vehicles, and water spray may create hazardous driving conditions.

Fenders limit this spray by covering the tires. Debris and water hit the fender instead of the cab or spraying out into the road. That’s why larger fenders provide more protection. When a larger part of the wheel is covered, debris is more likely to hit the fender than anywhere else. But when a truck has a half or quarter fender, it’s more likely that the debris will spray out from the tires. Good fenders that provide more protection can preserve your truck and keep other drivers safe.

Truck fender flares and their purpose 

When your truck has oversized fenders, a fender by itself won’t provide the necessary protection. In that case, owner-operators can purchase truck fender flares, which act as an extension of the fender. For example, if your tire extends from your fender, you can add a fender flare to expand its width for more protection.

Sometimes adding a fender flare may be a personal preference; in other cases, it’s required to meet legal standards. States have diverse requirements for preventing debris or water spray, including mud-flap regulations. If standard fenders don’t quite meet your state’s requirements, a truck fender flare is a simple solution.

Protect your truck and others on the road

Taking preventive measures to protect your truck is the best way to avoid pricey repairs. Fenders help you preserve your cab and ensure your truck won’t cause damage to others on the road. Choosing the right fender could protect your cab for years and help ensure your truck doesn’t cause hazardous driving conditions.


Do you have to have fenders on a semi?

Fenders, like mudflaps, are required on semitrucks to ensure debris spray from tires does not damage other vehicles on the road.

How much weight can a single-axle trailer hold?

Federal regulation states single-axle vehicles can haul up to 20,000 pounds.

Do fender flares allow for bigger tires?

Fender flares help extend fenders to protect oversized tires by extending the width of your fenders.

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