Front brake pads provide up to 70% of vehicle stopping power. In general, front brake pads wear out twice as fast as rear brake pads, 2 to 1. Disc brakes have a definite braking power advantage over drum style brakes and performance is not compromised as much when wet. Some disc brakes utilize cooling fins in-between the braking surfaces to maximize cooling efficiency. Replacing brake discs can vary depending on the make and model of car or truck, two wheel or four wheel drive. Always replace brake rotors with top quality or OEM (original equipment manufacturer) brake rotors, some less expensive brake rotors can squeak and not dissipate heat as well because of their inferior metal quality.