At what original size should you consider replacing brake pads?

Brake pads are a critical component of a vehicle's braking system, and their condition significantly impacts safety and performance. Generally, it is recommended to consider replacing brake pads when they have worn down to about a quarter of their original size. This guideline is based on ensuring that adequate friction material is left for effective braking performance.

When brake pads wear down to this level, they may not provide the necessary grip required for safe stopping, particularly under heavy braking conditions. Additionally, waiting too long to replace them can lead to further damage, such as scoring of the brake rotors, which can incur higher repair costs.

The other options represent sizes that are generally still deemed acceptable for use, but they put the vehicle at increased risk of performance issues and potential safety hazards if not addressed soon. Therefore, the one-quarter mark serves as a crucial threshold for assessing the need for timely maintenance to ensure optimal vehicle operation.