I don't know if I am ever going to replace the pads an my '80 300SD. I have about 115,000 on the car since I bought it in '90 (227,000 total) and it still has the same pads in it. They look less than half worn out now. I make a lot of long trips where brakes might not get used for 100 miles or more and I downshift on some hills..
P E H