Cross drilled rotors

[someotherguy]

Cross drilled rotors were developed to aid in venting gasses that were formed under pads of older disc brakes. The pad material would create a cushion of gas between the pad and rotor, reducing the effectiveness of the brakes. The holes in a drilled disc would allow this gas to escape and improve brake performance in racing applications. However today pads do not have this problem, as materials have come a long way. Drilled rotors are in no way beneficial to disc brakes today. In fact you will not find race cars with drilled rotors. Slotted rotors are a different story...

So in short do not buy drilled rotors! They tend to crack and cause problems. Plenty of material out there about this topic, interesting stuff!

Pretty much this ^. Cross-drilled is simply bling, even on a few higher-end cars that come with them OEM - it's to suit a certain "racer" image that some people think the car should have. Smooth is fine, slotted is fine, cross-drilled is counterproductive. Look at it this way - swept area is one of the big factors in braking, and all those holes subtract from that area. That's friction surface you are losing to what has become a useless gimmick.

Richard

 

[NorCalMike]

Cross drilled rotors always remind me of a cheese grater, and in my experience, work pretty similarly. But instead of making some good tacos, they make dust out of your pads.

 

[sewlow]

The holes are chamfered to reduce that cheese grater effect.