Should you get cross drilled rotors or slotted rotors?  This is a common question and the answer really depends on the driving conditions you deal with on a day to day basis. 

 Below we have provided a breakdown of the two designs and how they compare in regard to certain qualities other than aesthetics:

Stopping Power

 Slotted rotors are the preferred design by race car drivers when it comes to stopping power.  Slots provide brake pad bite and cooling ability of the friction surface, which results in better performance.  This system is also said to be a lot more efficient during wet weather, because its design directs water away from the friction surface, thereby reducing the risk of waterlogged brakes. 

For cross-drilled rotors, it is the pedal force in relation to its stopping power that is usually complimented by experts.  This is because the driver does not need to exert much force on the brake pedal in order to make a stop, most especially if the brakes are running at high temperatures.  In effect, this system has additional safety features in regards to braking response and is said to help in the reduction of driver fatigue.

Thermal Capacity/Heat Dissipation

    *source:  siemens.com

 Slotted rotors have a higher thermal capacity than drilled rotors and are preferred over cross-drilled rotors for more demanding braking conditions like racing or towing.  Race car drivers use their brakes heavily and in extended periods of time.  As a result, brake parts overheating and premature brake stoppages can be a big issue with the wrong brake system.  Drilled rotors can crack under the tremendous amounts of stress that racing causes and is not ideal for this application.

 Cross-drilled rotors are more for drivers that use their cars brakes in short or moderate periods of time, such as normal, street and highway use.  This system can dissipate heat more quickly because of its design; thereby having a higher coefficient of friction.  In other words, because it dissipates heat more quickly – then it will be efficient when used in short or moderate intervals as the brakes will cool faster compared to the slotted rotor system.

Usability

Slotted rotors are designed for the easy removal of water, gas and other debris which may be accumulating under your brake pads.  This design is applicable in racing, towing, or every day, street and highway use.

Cross drilled rotors offer the most benefit for everyday street use.

Whether brake rotors are cross-drilled, slotted, or both, they all serve to keep the brake pad material fresh, provide more bite, and allow hot air and gasses to escape during braking.  It is only with more demanding driving conditions is when there will be a difference.