What are wheels?

To understand the difference between wheels and rims, it helps to know how automobile wheels work. Let’s start with the basics. While sometimes people think of tires when they talk about wheels, technically your wheels and tires are separate entities that ultimately combine to form the tire-wheel assembly.

Rims play an important role in this setup. As the outer edges of the wheel, your rims secure the tire on to the wheel by forming an airtight seal. But rims are only one part of the wheel equation. In addition to rims, wheels are comprised of other important features:

• Wheel bearing: This is the part of the wheel assembly that connects the wheel to the axle.

• Lug nuts: Located around a wheel’s center, these nuts secure the wheel to the vehicle. 

• Center cap: These caps help keep dirt and grime away from the wheel bearings and lug nuts. They often sport a manufacturer’s logo.

• Hubcap: Larger than center caps, these disks are hammered or clipped on the hub of the wheel, covering the lug nuts. Hubcaps used to be more common, helping protect steel wheels from the corrosive effects of winter weather, road salt and other harsh chemicals. Nowadays, wheels are increasingly made of aluminum or metal alloys, which tend to better protect against corrosion, making hubcaps less of a fixture.

• Spokes: These are the metal arms that connect a wheel’s center to its outer reaches, such as the rim and the barrel.

• Barrel: While your rims are the outward-facing edge, the curved portion of the wheel outside of the spokes is known as the barrel.

• Wheel cover: A wheel cover helps protect the entire surface of the wheel. Wheel covers are often designed to make the wheel look more appealing and may also be used as a cosmetic fix for minor scratches.

What are Rims?

As we mentioned, the main difference between wheels and rims is not technically a difference at all: rims are simply one important part of the wheel. Of course, in popular culture the phrase “Nice rims!” has long been used as shorthand for complimenting someone’s wheels, particularly in reference to a sharply designed or intricate wheel cover. But what we’re talking about here is what rims actually are: the two outer edges of each side of your wheel.

What do Rims do?

As the edge points of contact between the tire and the wheel, rims help hold tires properly in place. As stated, they also help maintain an airtight seal between the tire and the wheel.

For these reasons, your rims play a crucial role in supporting the entire wheel assembly and its place in your car’s suspension system. If you drive over a bump or pothole, the rim is the part of the wheel that receives the initial impact after it passes through the tire.

You may think of your tires and rims as the front line of defense against the rigors of the road. If your rims get banged or dented, it may affect the performance of your vehicle, from flat tires and reduced handling to distracting vibrations inside the cabin.