Heavy vehicle braking pad designs vay with the weight,application and vocaton of the vehicle....heavy vehicles in severe braking apps will see the best lining wear with carbon metlic linings, while lighter vehicles will be best seviced using organic or semi organic linings.....but it is impotant to factor in the wear on braking surfaces as severe duty linings will erode these more quickly....also severe duty linings will tend to glaze over if not used hard for the application they were designed for such as in light
duty apps causing brake squeal and poor light brake application performance...conversely, if the lining is for lighter duty that actual service encountered, then expect not only extreme lining wear but also fade under heavy braking, possibly fire and loss of braking altogether...