How Long Do Brake Pads Last?

Mechanics and manufacturers have loosely agreed upon mileage range from around 48,000 to 112,000 km, but stories of pads lasting a mere 160 km to an astounding 160,000 km abound.

These far-ranging numbers are understandable. Pads come in an array of types and compositions - from composite to metallic to ceramic - and are attached to an even more bewildering array of brake systems and rotors, all of which affect the life of the pad.

Let's begin addressing the longevity question by looking at what brake pads are made of, or their frictional material. Pads generally come in four types: organic, semimetallic, metallic, and synthetic. Each of these types has their own characteristics that must be weighed against brake pad life:

• Organic: Made from non-metallic fibers bonded into a composite material. The material is then treated with friction modifiers including graphite, powdered metals and even nutshells. Fillers are added to reduce noise and to affect heat transfer, among other factors.

• Semi metallic: This pad is a mix of organic material and metals - ranging from steel and iron to copper - molded and bonded to form the pad. These pads are harder and more resistant to heat.

• Metallic: This material, formed of a variety and mix of pressure bonded metals, was once used extensively in racing. Advances in organic and semimetallic pad composition have made metallic pads almost obsolete.

• Synthetic: This is what is often referred to as ceramic pads. These pads are made from a composite of non-organic and nonmetallic material, usually fiberglass and aramid fibers. These pads weigh about half the weight of the average pad, they are stronger, have better cold and hot stopping power and they last much longer than the average pad. They also cost about twice as much.

For the pad materials above, the best stopping power is found in the organic pads. But this same stopping power means more of the pad material is worn away during a stop. Because of this, organic pads last the least amount of time on average. Semimetallic pads, the pads that are now on most cars, are harder and last longer but they don't stop as effectively as organic pads do. The same goes for ceramic pads, though these pads do often last longer if the driver is willing to pay the price and have a slightly longer stopping distance.