My Mazda 6 is just under three years old with 24,000 miles on the clock. I was told that the pads and discs need to be replaced all round. My first service at 7200 miles noted 8mm on the pads, the second service at 15,800 miles noted 7mm wear. A year later, I'm getting a grinding noise off the back brakes and rust on the alloys. I'm not hard on the brakes, using the gearbox in conjunction with the brakes to slow down. What mileage should I expect to have to replace pads and discs on a Mazda 6? My last car was around 60,000 miles when this happened, and from what I can see on the net, that's pretty standard.