Brake Rotor Replacement: Slotted, Smooth or Cross-Drilled?
February 10, 2019
BY BENJAMIN HUNTING / ORIGINALLY PUBLISHED APRIL 12, 2018 / NATIONAL AUTOMOTIVE PARTS ASSOCIATION /
When considering brake rotor replacement, you may be tempted by several of the options that are presented to you to enhance your vehicle’s stopping power. In fact, there’s a small universe of bolt-on brake parts out there that are intended to upgrade your stock components without asking you to make any modifications to your vehicle, and rotors are no exception.
Which brake rotors should you consider for your vehicle? Check out our breakdown of the three most common types of rotors you’ll find when it comes time to replace your worn-out set.
1. Slotted Rotors
Slotted brake rotors get their name from the channels, or slots, that are machined into the surface of the disc. Typically, these brake rotor replacement parts feature angled slots that arc out from the center, or sometimes radiate in a in an S-groove pattern.
The concept behind a slotted design is to provide an escape channel for the gas and dust that’s produced by your brake pads when pressed against the rotor. Instead of building up on the surface, these elements escape through the slots, reducing temperature thereby improving stopping performance by allowing the pad to make more direct contact with the disc.
One down side of slotted rotors is that the edges of the slots scrape against your brake pads, which may require more frequent replacement intervals.
2. Cross-Drilled Rotors
Cross-drilled rotors take a different approach to venting gas and heat by way of the holes that pass directly through the entire disc. These are geared more for high-performance and track driven vehicles where braking effectiveness is more important than longevity. A shortfall of this design is the holes can actually weaken the disc and can cause cracks to occur under extreme braking, similar to what you would encounter in a high-performance driving situation.
You can go all the way and purchase brake rotor replacement parts that are both slotted and cross-drilled, but you may not be happy living with the after effects on a daily driver street car.
3. Turned or Non-Directional Rotors
Turned or non-directional rotors — also known as stock replacements — offer none of the trade-offs of cross-drilled or slotted designs. Strong, durable and able to offer their complete surface to a brake pad, turned or non-directional rotors are often the best all-around choice even for everyday drivers and those looking for improved performance and pedal feel.
Slotted and cross-drilled rotors are certainly stylish, but smooth is often the best way to go when sourcing brake rotor replacement parts. A reality check about the type of driving you are most likely to do with your vehicle will help you make the best decision for your needs.
Check out all the brake system products available on NAPA Online or trust one of their 16,000 NAPA AutoCare locations for routine maintenance and repairs. For more information on brake rotor replacement, chat with a knowledgeable expert at your local NAPA AUTO PARTS store.
Photo Credit: Front disc brake, 2003 Dodge Caravan by Dave Fischer (CC BY 2.0).
This article has been reproduced with the permission of the copyright holder, National Automotive Parts Association. Further reproduction is prohibited without permission. Click here for more automotive tips and stories from NAPA, or here for more information on the next Pomona Swap Meet & Classic Car Show.
Spot on! If you believe that brake dust sticks to your pads, you’ve obviously never looked at your wheels or changed brake pads. What do you think that black stuff on your hands and the wheels is? Slotted and drilled rotor do wear out brake pads quicker. Additionally, there are wild temperature fluctuations in drilled rotors that cause cracks due to uneven expansion. The only braking improvement you’ll have with slots or holes will be all in your head. If that’s the case you should also buy one of those dumb little fans that fit in your air intake system. You’ll really enjoy the extra 30 HP gain and 20% increase in gas mileage that will also be in your brain.
I agree with this article, I’ve tried high performance pads and rotors and they wear out quickly and I can’t say I noticed any additional stopping power, they just cost more.