I bought these pads for my 1989 Supra ChumpCar endurance racer. These 4610R pads are for the front wheels, we also bought matching 4806/2R pads for the rear wheels. We used them for 14 hour road races at Atlanta Motorsports Park last November. The front side still has about 20% base thickness left, the back side about 75%. They worked well with no fading or visible damage from overheating. They creak a bit in the cold, so I don't recommend them for outdoor use.