In automotive disc braking systems, a pair of brake pads squeeze against a rotor, providing high friction to slow rotation. Brake pads in modern vehicles are either ceramic or metallic. Ceramic brake pads are usually more expensive but offer superior performance for casual drivers. Metallic brake pads perform better under the intense demands of racing, heavy trucking, and police work. The properties of metallic brake pads, in particular, involve a trade off of performance and longevity.
Performance & Wear
Ceramic brake pads offer great performance for most drivers. Ceramic pad manufacturers claim that because ceramic pads last longer, they actually cost less money in the long run. Early ceramic brake pads tended to wear down rotors more quickly and performed poorly until warmed up, so this argument failed when considering the cost of frequently replacing the worn rotors. However, modern ceramic pads have overcome the issues and are not as rough on the rotors.
Metallic brake pads are cheaper and less abrasive on rotors, but come with the trade off of more noise, dust, and overheating. Metallic brake pads offer higher braking performance in heavy duty applications such as heavy towing and sudden stops.
For the average driver, either type of brake pad will certainly perform well enough under most conditions. The decision is basically between cheaper metallic pads that produce more dust, noise, and wear more quickly (but are easier on rotors), or the more expensive and longer-lasting ceramic pads that are quieter, cleaner, but may damage rotors.
How Disc Brakes Work
This video describes the mechanism of how disc brakes work:
Ceramic brake pads represent the most recent technology, and are created using a combination of ceramic material and copper fiber. Ceramics are nonorganic, nonmetallic substances created by the action of heating and cooling to form a crystalline structure.
Metallic brake pads are made of steel fibers or iron powder blended with the braking compound. Metallic brake pads have been around longer, and originally emerged as a replacement for asbestos brakes, which released a dangerous dust over time.
Ceramic materials benefit from high stability under heat, i.e., heat spreads evenly through the material. Heat also dissipates more quickly from ceramic brake pads, providing a quicker recovery time after heavy braking, potentially lowering the risk of brake failure on long descents. Because the ceramic pads draw less heat, more heat remains in the rotor, which can cause rotor warping in extreme conditions.
Metallic brake pads draw more heat and hold it longer than ceramics, but with the benefit of keeping the rotors cooler. In prolonged instances of heavy braking, metallic pads run the risk of glazing over and becoming less effective.
Noise & Dust
Ceramic brake pads are quieter than metallic brake pads because they vibrate at a frequency above the range of human hearing. They also produce less dust than metallic pads, and the dust that they do produce is lighter in color and easier to wash off.
Metallic brake pads are noisier and produce more dust. The dust commonly discolors wheel rims, and is difficult to clean off. The dust, though far less dangerous than asbestos brake pad dust, is still not good to breath in.
Pricing and Purchase
If you are still evaluating, the Amazon's Best Sellers list will give you an idea of which replacement brake pads have been selling the most.
- Why Ceramic Brake Pads? - TireRack.com
- Ceramic Brake Pads vs Semi-Metallic. What Are The Differences? - Performance Brake Blog
- What are The Best Brake Pads: Ceramic or Metallic? - AutoAnything