Hubcaps vs. Rims: Understanding the Difference

For some, a car is just a way to get from point A to point B. For others, it’s a canvas for personal expression. That’s why we have political bumper stickers, Garfield window decorations, and custom paint jobs, some featuring flames.

One place where people like to get creative is with their wheels, or rims. But rims aren’t exactly wheels, and hubcaps aren’t either. So, what’s the distinction?

Strictly speaking, a wheel is a circular object used for movement. While ‘rim’ is often used as a slang term for a wheel, it actually refers to the outer edge of the wheel that holds the tire in place. It’s like the rim of a cup. People usually call the wheel, rim, and tire together a wheel.

So, why do people say rim when they mean wheel? It may be because larger, flashier wheels have more noticeable rims, but the exact reason is unclear. (According to Green’s Dictionary of Slang, rim meaning wheel dates back to 2000, so it might be a more recent trend. Green’s also tells us that rim slide is prison slang for flatulence. Make of that what you will.)

A hubcap is the cover made of plastic or metal that fits over the center of the wheel, or wheel hub, where the wheel is connected to the vehicle. Typically, a hubcap protects against rain and other elements that may cause corrosion. Not all wheels require hubcaps, as modern vehicles often use wheels made from aluminum or metal alloys that don’t corrode as easily as steel.

Cars can also have wheel covers that encompass the full diameter of the wheel, though people still commonly call them hubcaps. Why? Probably because ‘hubcap’ has become a general term for anything that shields the wheel. But technically, a hubcap doesn’t have to reach the rim – it just needs to cover the wheel hub.

Here’s another way to think about it: Rims are essential for securing the tire to the wheel; hubcaps are optional. A car is optional too, depending on how walkable your city is, but that’s a different conversation.