Dear Tom and Ray:
I have a 2000 VW Golf 1.8T, which I have enjoyed owning -- except when I have taken it to the shop for brake pads. When I brought it in at 40,000 miles, the dealer told me that I needed not only brake pads, but also rotors. He informed me that Volkswagen makes thin rotors that are not able to be resurfaced. He said they are designed to wear out with the pads. Is this true? And why would they intentionally make thin brake rotors that have to be replaced every time you change the pads? -- Pax
TOM: Surprisingly, it's to keep customers from complaining, Pax!
RAY: It's all about noise. In the old days, brake pads were made of asbestos. Asbestos was a perfect material for brake pads (except for that little issue of lung disease). It was durable, it performed well at high temperatures and it was relatively soft, so it didn't squeal when it made contact with the hard steel rotors.
TOM: And with the softer asbestos pads, the pads would wear out over time (as they were designed to) but leave the rotors relatively unscathed.
RAY: Because of the dangers of asbestos, we now use metallic brake pads. When the hard metallic brake pads squeeze the hard metal rotors, they make noise. And customers -- as I can personally attest -- hate brake noise.
TOM: So over time, manufacturers, including VW, have softened up the rotors to get rid of the squealing. VW is not alone in this. All manufacturers have done it.
RAY: But as a result, the rotors wear out almost as fast as the brake pads do. And they often wear out so much that they end up being too thin to machine.
TOM: Now, the manufacturers could simply make their rotors thicker. But making steel rotors thicker adds a lot of weight, which reduces gas mileage.
RAY: So the reality is thinner, softer rotors, which are inconvenient and costly for you, Pax. But look on the bright side: You're helping the guys in the parts department to send their kids to private colleges.