What Is a Fender On a Car? [Complete Guide]

Whether you’re a new or an experienced driver, might have heard the term “fender car” or “car fender”. So, what is a fender on a car? This guide will walk you through what a fender is and how it relates to a vehicle.

Fenders are curved panels extending from the front bumper to the door, shielding the wheels. Made of plastic, metal or rubber, fenders keep debris off tires and brakes for safety and efficiency. By preventing spray from rotating tires, fenders also protect other vehicles. Attached to the car’s frame, fenders come in various styles and sizes.

What Are Car Fenders Made Of?

Depending on the model of the car, fenders are made of metal, plastic, fiberglass, rubber, etc. They are designed to protect the sides of the car from damage due to road debris, water, etc.

For instance, for Lamborghini Gallardo, the fender is made of a thermoplastic material. For Audi R8, the fender is made of plastic. For Audi A6 and A7, the fender is made of aluminum. For Mercedes-Benz SL (R 231), the fender is made of aluminum. For BMW presented with the 5 and 6 series, the fender is made of 18% aluminum alloy.

Are Car Fenders Important?

Yes, car fenders are very important to protect your car from being damaged by road debris such as pebbles, stones, sand, and other things that may get stuck in the wheel wells.

They will also make your car look better and more stylish. They will keep your car safe from all sorts of damage caused by road debris and rainwater.

According to the Minnesota Government, every passenger automobile shall have fenders that are designed to prevent, as far as practicable, water, dirt, or other material being thrown up by the wheels.

In the United States, aside from cars, fenders are installed on motorcycles, trucks, and ATVs. The fender itself is a part of the car’s body over the wheel well. Wheel well is the area where a wheel is turned.

How Do Car Fenders Offer Protection?

The car fenders protect the sides of the car from splashing water, dirt, rock, and other fluids on the road as you drive. The liquid spills on the road can damage your car’s body paint.

As the tires spin very fast on the road, they have very high kinetic energy (rotational energy) to eject particles at high velocities. If that happens, the dirt and splashes of mud can:

• Get the vehicle dirty
• Crack the windshield or body of another car beside your car
• Get the pedestrians dirty
• Protect the vehicle from scratches

That’s why Fenders are mandatory to install as they will protect your car body against any scratches or splashes. Moreover, fenders improve the aerodynamics of the vehicle.

As the tires rotate at high speed, they cause a lot of drag by creating turbulence around them. A curved enclosure of a fender over the wheels helps to reduce that turbulence and improve the aerodynamics of the car.

What Parts Does A Fender Assembly Have?

A fender is a key body panel on cars and other vehicles that serves several important functions. Let’s break down the various components that make up a typical fender assembly.

Outer Fender Panel

The main visible part of the fender is the outer fender panel. This larger panel comprises the majority of the structure and is the main body component that we see on the exterior of the vehicle. Some key attributes of the outer fender panel include:

• Made of sheet metal, usually steel but sometimes aluminum on high-end vehicles
• Formed into the curved fender shape
• Contains holes and brackets for mounting trim, lights, badging, etc.
• Painted as part of the exterior body color
• Provides essential clearance around the wheels
• Protects mechanical components from road debris

The outer fender comes in front and rear pairs, with the fronts being slightly more complex in shape. But the basic purpose and construction is similar between front and rear.

Fender Liners

Fender liners, also known as inner fender liners or wheel well liners, are components made of thermoplastic that attach to the inner fender. Key features and purposes of fender liners include:

• Protect critical components like suspension, steering, and brake parts from debris
• Absorb noise and water splashing from the wheels
• Can be removed for wheel well access when working on other components
• Available painted or unpainted in black plastic

Note: The material of fender liners of older vehicles is still metal. Modern vehicles have thermoplastic fender liners.

I have also found this guide on inner fender liners really helpful. You must read it.

Fender Supports and Brackets

Between the inner and outer fender panels, there are various metal support brackets and gussets that connect the two layers together and provide structural support. Common supports include:

• Fender braces around headlights and turn signals
• Inner fender gussets at corners and wheel openings
• Mounting plates for fender bolts and tabs
• Strut tower support brackets

These supports serve to rigidly bridge the gap between the panels.

Fender Trim and Moldings

Decorative trim pieces provide styling accents and protect the fender edges from rock chips and debris. Typical fender trim parts include:

• Fender flares made of plastic or fiberglass
• Chrome side moldings running along the body
• Painted or metal edge guards around wheel openings
• Stone guards and mud flaps behind the wheels

Fender Hardware

Various hardware components attach the fender assembly to the vehicle. Common mounting hardware includes:

• Fender bolts, washers, and nuts
• Plastic push pin fasteners
• Rivets and bonded nut plates
• Alignment adjusters and shims

Proper installation of mounting hardware ensures the fender assembly remains attached securely.

What Are Fender Flares?

Fender flares are aftermarket accessories that bolt or stick onto the fender edges of trucks, SUVs, and other vehicles. They create wider wheel wells that allow larger tires to be installed without rubbing against the body. Fender flares serve both functional and aesthetic purposes on trucks and certain vehicle styles.

Here are following purposes of fender flares:

• Protect paint and body panels from rocks, mud, and debris kicked up by the tires. They act as mudguards to prevent scratches, chips, and damage to the sides of the vehicle. This is especially useful for off-roading.
• Allow fitting larger tires without rubbing or wearing against the fenders. Wider tires require more clearance from the body, so flares create the extra space needed.
• Meet legal requirements in some states for how far tires can stick out from the fenders. Having tires that extend too far out is illegal in certain places.
• Help minimize dirt, mud, and grime from splashing up onto the doors and side panels. Keeps the vehicle cleaner compared to not having flares.

Some common brands for fender flares discussed are:

• Bushwacker – Popular pocket style riveted flares. Most recommended overall.
• Lund – OEM style smooth flares that blend with body lines.
• Rough Country – More affordable pocket style flares.
• ATS – Another popular pocket riveted flare brand.

Styles of flares include:

• Pocket riveted – These flare out from the fenders with visible rivet attachments. Bushwacker is a leading brand.
• Smooth OEM – Follow the body lines for a more integrated look. Don’t flare out as much. Lund is a top choice.

Why Do F1 Cars Have No Fenders?

F1 cars have no fenders because they have traditionally been designed like this as it is perceived as being an essential part of the sport.

Adding fenders to F1 cars would move away from the tradition in Formula 1 racing as it is classified as ‘Open-wheel racing’.

It would also make the cars heavier, and the teams would need to invest millions of dollars into fender developments in a series that focuses on cost-cutting.

The reason behind these F1 cars having no fenders is to give them the ability to turn quicker by increasing the downforce.

When a downforce on a tire increases, it also increases the grip of the tire on the racing track. This allows the F1 car to take quick turns without losing balance. Moreover, open wheels and no fenders on F1 cars eliminate the weight to help them accelerate faster and accelerate fast.

What Is The Difference Between Front and Rear Fender?

The main difference between front and rear fender is that front fenders are typically separate bolted-on pieces made of thin metal or plastic. This allows them to be easily removed for repairs or replaced after minor accidents.

Rear quarter panels are often part of a unibody, welded together with other body panels. This provides structural rigidity but makes repairs more difficult.

Having removable front fenders aids assembly line production, where engines can be installed before attaching fenders. Welded quarter panels take more skill to properly align.

Some vehicles like the Saturn used plastic removable quarter panels, but this is less common.

On SUVs and trucks that have been leveled, the front fender sits 1-2 inches higher than the rear to maintain clearance for the front wheels when turning.

Now, you might be thinking why are front and rear fenders designed differently? Here are some of the primary reasons:

• Front fenders need to allow room for suspension movement and wheel turning radius.
• Front fenders experience more minor collisions, so need to be easily replaced.
• Separate front fenders aid access for assembly and service.
• Rear fenders are structurally integrated for passenger protection.
• Front fender damage doesn’t affect door fitment like rear quarter panels do.
• Plastic bolt-on fenders are cheaper to replace than welded steel panels.
• Front fender shape has less impact on body lines versus rear.
• Rear fender repairs often require cutting out and welding in new sheet metal

What Is The Difference Between A Fender And A Bumper?

The main difference between bumper and fender is that a bumper is installed on the rear and front of the vehicle while the fender is installed over the front and rear wheel wells on the side of the car body.

Bumpers absorb shock when cars collide with another body, while fenders prevent dirt and other particles from entering the wheel well, as well as improve the aerodynamics of the car.

Fenders can also act as the extension of the bumpers as they also have the ability to absorb the impacts of minor collisions.

In the past, the bumpers on cars used to be separate frames, made of rubber. Now, bumpers are metal or plastic frames screwed into the car body. Similarly, fenders are also metal frames screwed into the body of the car.

How Many Fenders Are On A Car?

Technically, there are a total of 4 fenders on a car, each over the four-wheel wells. The two fenders on the rear wheel wells are typically called quarter panels instead of fenders. 

In US automotive design industry, the fender typically refers to the front frame covering the wheel, and the quarter panel is the rear panel covering the rear wheel wells and C-pillar.

You can see quarter panels right between your car’s rear door and the trunk/bed. Like fenders, quarter panels usually extend above and around your rear wheels.

The main difference between fenders and quarter panels is that fenders are bolted on while quarter panels are typically welded on.

So, in terms of auto industry nomenclature, a car as two fenders on the front.

Can You Replace Fenders?

Yes, you can replace fenders that are over front wheel wells. Fenders are screwed into the car body.

Replacing fenders on a car seems easier, but it is quite difficult if you’re a beginner. You will have to find screws holding the fenders and unscrew them using special tools. It is quite difficult to access the bolts, clips and screws of a fender to replace it.

The following tools are usually needed to remove the car fenders:

• Phillips Head Screwdriver
• Flathead Screwdriver
• Ratchet
• Plastic Trim Tool
• Pliers
• Ratchet Extensions

Removing the fender from the car body depends on the model of your car. You have to partially remove the bumper to remove the hidden bolts of the fender. 

Moreover, if you look under the wheel well arch, you will find hidden bolts/screws. They are usually made of plastic. It is easier to remove them.

The headlight of a car has a tab that is alao screwed into the fender. You might also have to remove that. If you pop up the hood, you will also see the bolts under the rubber trim cover along the boundary of the hood.

There might also be some bolts inside the door opening, near the door hinge. If you have owner’s manual, you can locate al bolts, clips and screws of the fender.

Keep in mind that rear fenders i.e. quarter panels can’t be removed in your home garage.  Quarter panel is butt-welded or spot-welded to the roof frame of the car.

The welding seam of quarter panels is covered by filler before the body is painted. So, it’s a very labor-intensive task to remove the quarter panel (Rear fender) without destroying the car body structure.

Cost of Fender Replacement

For fender replacement (front fenders), the cost depends on the kind of fender, where the fender was damaged and the extent of damage.

According to the survey, the cost to replace, paint and install a new fender can go anywhere between $600 and $1500.

The cost usually goes above $1000 when the front bumper also gets damaged with the fender. The cost to replace a car fender also depends on the area in which the auto shop is located.

How Do You Fix A Car Fender?

A fender can be damaged through an accident or a collision with another vehicle or object. The most common problem with a fender is a dent.

It is caused by hitting another object or being hit by another vehicle. In some cases, a fender may be bent or cracked. So, the method of fixing a car fender depends on how it is damaged.

1. Fixing Dents On a Fender

If there is a light dent on the car fender without any crease as shown in the below picture, you can go for a PDR (Paintless Dent Repair) technique.

I have left a Youtube video below to learn the PDR technique to remove a dent in the fender. This guy is good. You can also watch his other videos.

You can also repair a dent in a fender by using a hammer and dolly. If you don’t have those tools, you can use a small pry bar to remove the damaged portion.

Get a pry bar behind the fender pushing out on the dent, and hit on the outside of the fender above the dent. Make sure that the hammer is fully polished.

You can check out the below video for a better understanding:

2. Fixing Cracks On a Fender

If there is a crack on the fender, first drill a small hole at the end of the crack to prevent it from further cracking. Your mechanic can try plastic welding on it or buffing it down with sandpaper and applying epoxy on it if the fender is made of plastic. If the fender is metal, you can drill holes on both sides of the crack and pop-rivet both sides to the aluminum plate. You can read this forum thread for more details.

Final Thoughts

Car fenders are an important part of your vehicle. They protect the car from damage caused by road debris. Keeping this in view, it is important to keep the car fenders in a good condition.

There are two ways to protect your car fenders. First, you can buy a new set of fenders when they are damaged, and second, you can repair your fenders if you’re an expert or have a professional mechanic.

The first method is easy. You just need to buy a new set of fenders. However, this is not always the best solution. Some people may not like the idea of buying new fenders because it’s expensive.

Another method is to repair your fenders. It is not as easy as it sounds, but it is still possible. You just need to know how to fix your fenders. I’ve tried my best to explain to you the most common methods of fixing damaged fenders.

I would highly recommend you visit a professional mechanic to fix the fenders. Otherwise, it can worsen the condition of dents or cracks on the fender.