The Audi Brake Rotors & Discs are made specifically for this unique type of automobile. They do not always interchange between models of cars within the Audi family itself. The reason for this is each one has a specific thickness, diameter and stud alignment that must match perfectly with what the engineers had designed for your make and model. Any variation from these specifications can reduce the efficiency of your braking system, or cause a braking failure to occur. Another useful piece of information for an Audi owner to know is the difference between the brake rotors and discs. The term rotor is used for a part that slips over the hub of the wheel with holes in it for the wheel studs to fit thru. With the wheel correctly mounted, the disc will be firmly held into place under all driving conditions. This is a term in American English. In Europe the term for the exact same part is simply called a disc. Your Audi Brake Rotors & Discs is the actual part of your braking system that slows the kinetic energy of your vehicle down. This occurs when the brake rotors & discs has pressure applied to it in a squeezing motion from the brake pads that are mounted inside of the calipers of your Audi. The lighter the pressure, the less force on the brake rotors & discs is applied. The master cylinder of your braking system is the device that regulates the pressure to each caliper applies. The front brake rotors & discs receive nearly twice the force as the rears do as it was designed by the engineers. Because of this the front brake pads generally need to be changed twice as often as your rear brake pads.