on the contrary, cars equipped with slotted disks experience
better wear rate on their brake pads. the grooves function as a
channel for brake dust (brake dust forming between disks and pads
during braking reduces braking efficiency) to be removed thus
improving contact between the disks and the brake pads under severe
braking conditions.
cross drilled rotors perform a similar function except they do so
by ventilating the contact area between the disks and brake pads
through the holes found on the disks.
IMO, these features (x-drilled and slotted) are only effective
under tremendous braking conditions, when the need for consistent
hard braking is higher. under normal driving, they nothing more
than reduce the contact patch as less metal on the disks comes into
contact with the brake pads at any given time (more holes/ slots
means less contact area). they also form poorer heat sinks as more
material is removed per volume of the disk (when u slot or drill a
disk, u remove metal from it). therefore, using the same material,
a xdrilled/slotted disk is able to take less heat compared to a
full brake disk before it starts to overheat.
