To Drill or Not to Drill?
    That IS the Question... Here is a short piece written about the differences
    between cross-drilled/slotted and slotted only rotors.

    Regarding which brakes are better stoppers......

    Assuming all the other variables remain unchanged, cross drilled and slotted rotors will
    almost always deliver better braking figures than other types. The  improved cooling effect
    of these rotors allows effective use of the brake system under extremely severe conditions
    (as might be seen in racing). The down side to this design is that when these rotors are
    forced to work to capacity for prolonged periods, they are subject to cracking around the
    drilled holes as a result of constant overheating and cooling. Until they destroy themselves
    these are the most efficient. For street use (long track racing), cross drilled rotors are
    perfect most of the time as the system is seldom used to capacity. The rotors should last a
    normal life span.

    If the rotor is of only marginally adequate specification for the vehicle weight or use, cross
    drilled rotors can be problematic and require frequent "crack checking" and possible
    frequent replacement. Under these conditions, slotted only rotors are more desirable.
    Slotted rotors are less prone to cracking under severe service than drilled. What they lack
    in efficiency (if any) they make up for in longevity. You will seldom find a high performance
    short track racecar with drilled rotors, these cars are almost always fitted with slotted
    rotors for the reasons listed here.

    If we had to stop hard one time from high speed, we would probably select a drilled and
    slotted rotor. If we had to do it over and over, we would almost certainly use slotted

    Hope this helps!!
Revolution Brake LLC
130 'A' Street
Ashland, OR 97520