What type of brakes are being gradually replaced by four-wheel disc brakes?

The type of brakes being gradually replaced by four-wheel disc brakes is drum brakes. Drum brakes consist of a hollow drum that rotates with the wheel and brake shoes that press against the inside of the drum to create friction and slow down the vehicle. While they have historically been used in many vehicles, particularly in the rear braking systems, four-wheel disc brakes are becoming more popular due to their superior performance, especially in terms of heat dissipation, stopping power, and maintenance.

Disc brakes, on the other hand, utilize a rotor that rotates with the wheel and calipers that squeeze brake pads against the disc to provide braking force. They tend to perform better in high-stress conditions (like heavy braking or high speeds) compared to drum brakes, which can suffer from fading and reduced effectiveness due to overheating.

As automotive technology evolves, manufacturers are increasingly adopting four-wheel disc brake systems for their improved safety and reliability, resulting in a decrease in the usage of traditional drum brakes in modern vehicles.