For high performance and heavy duty street conditions the Porterfield R4-S compound remains a top performer in the realm of street/performance brake pads. With the R4-S compound giving a friction level up to .41. This is an amazingly fast stopping brake pad. Simply put, they will give you an impressive increase in stopping ability with very minimum amount of pedal effort. Perfect for prolonged everyday street driving while also being capable of enduring the most severe use without fade. It is also rotor friendly of course.