The front brakes do the majority of the stopping, so having confidence in their ability is paramount. We recommend replacing the discs when changing brake pads as it can save you time and money in the long-term, as well as giving peace of mind in the braking ability of your X3. These Zimmermann rotors are manufactured in Germany and come with their anti-corrosion Z-Coat technology that prevents surface rust from developing. Zimmermann is an original equipment supplier to BMW.