Despite what you may think, some new cars still come with old-school drum brakes instead of modern disc brakes. Drum brake technology is old, outdated and not nearly as effective as modern hydraulic disc brakes. So one may begin to wonder, why keep using drum brakes at all? Before we get into that, we want to make sure you understand the difference between drum brakes and disc brakes. Once you understand the difference it’s easier to understand the rest of this mild conundrum.

What’s the Difference?

drum brakes
Here's a drum brake partially disassembled. 

Drum brakes utilize a mechanism with brake shoes inside a metal barrel-like housing or cylinder called a drum. When you step on the brakes the brake shoes are pushed out and rub on the inside of the drum creating friction that slows down the car or motorcycle or whatever vehicle you’re driving.

Disc brake!
Here's a close up look at a fully assembled disc brake. 

With disc brakes, there’s a disc, calipers and brake pads. The calipers force the pads into contact with the disc when you step on the brake pedal which then creates friction and slows down the vehicle. Both do the same thing (slow the car down by using force and friction) but in different ways.

Why are Drum Brakes Still Used?

silly Taco still uses drum brakes
Toyota's 2016 Tacoma still uses drum brakes in the rear. 

Old technology is typically cheaper to produce. So, even putting drum brakes only on the rear of the vehicle (which many automakers do because most of your stopping power comes from the front anyway) can keep costs down.

In addition to keeping costs down, disc brakes generally don’t work as well as a parking brake or an emergency brake. Additional equipment is needed to make disc brakes into competent parking brakes, once again raising costs. If you have drum brakes, you’re getting regular brakes and a parking brake in one system -- a very cost effective solution for the automaker.

Are Drum Brakes Obsolete?

Drum Brake Graveyard
This obsolete technology has been slowly fading from use for some time. 

Yes, drum brakes are obsolete in the sense that they’re outdated and not as widely used as they used to be. However, they are still used, especially on cars that are built on a tight budget and not used for high-performance purposes. Drum brakes on the rear of a vehicle will probably continue to be used for a while, especially on pickup trucks and economy cars becuase it will keep costs low and most stopping power comes from the front wheels anyway. 

Performance cars need disc brakes because they are so well balanced and the brakes have to be comparable to the performance of the engine. The last thing anyone wants is a fast car that can't stop. As time goes on, we’ll see fewer drum brakes across the board until eventually, they will disappear altogether.