The key difference between SS, SP and XP is the friction level and operating temperature(s).
The SS range has been developed for great friction performance, and a high level of comfort features such as low noise and low dust for general light duty street applications.
The SP range has been developed for optimal friction performance and longer life in street applications and light towing.
The XP range has a higher friction level and operating temperature. The addition of carbon fibre elements in the XP range, assists with better thermal stability at higher temperatures, when used in heavy duty applications.
Note: Wear and dust may increase in heavy duty applications.