Are drilled and slotted rotors worth the cost?
- Thread starter kitchbow
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I had a pair for a high end Grand Cherokee (Hemi). Did not notice a difference. They ended up warped about the same time as any other domestic vehicle I’ve had
edyvw
$50 site donor 2025
Very small if executed right. Mercedes had drilled rotors to help water evacuation. But carefully designed and of highest quality (very important if hole is drilled through rotors). Slots help with excessive gas that pads create during hardcore usage.
Depending on manufacturer, it might be dangerous. If they are not carefully designed and best materials used, avoid it. Or go dimpled rotors if you just want looks.
I ran a set on an HD trucks some 10 yrs ago. The big reason I bought them was that they had corrosion protection on them which worked well. I did not notice any improvement in performance. All things being equal I wouldnt go out of my way to use them. We used NAPA premium pads and rotors on the GMT800 trucks at work, they held up well to the abuse.
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In Europe there were a lot of kids driving hot hatches at outrageous speeds in the mountain passes. They talked about this too.
I can't say if that would change with a truck towing.
They're fine. I pretty much only use Powerstop kits anymore and they're fine. Not really better or worse
All those cheap drilled and slotted rotors look like straight up rice. Full face for me.
Waste of $$, but they look cool. I wouldn't buy them.
If there were any tangible benefits for these features, light duty truck manufacturers would have equipped their trucks with drilled and slotted rotors from the factory. Drilled holes and slots reduce the swept area of the rotor. I’d stick with a conventional setup unless you are racing.
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Mercedes does them right, and any AMG car, or Amg kitted E class will have them. You may have heard the two versions, Luxury or Sport E Class. My 2014 E class sport had them, my 2018 Luxury does not. I DO miss the look though. just personal preference. Both of these cars had excellent brakes though.
Aftermarket seems to be more of a gimmick judging from the comments here.
Aftermarket seems to be more of a gimmick judging from the comments here.
Holes or dimples does not add neither friction nor thermal mass.
Vehicles with drilled or machined dics from factory are sized accordingly.
Vehicles with drilled or machined dics from factory are sized accordingly.
Why would drilled holes crack more than drilled slots ?
My understanding is the best design is to cast the holes (or slots) in vs a machining step.
I’ve heard good things about Powerstop in general.
Yeah I mean they're fine. They look ok, they stop ok, they don't go wobbly immediately, and they're reasonably priced.
Solid rotors provide more surface area interacting with the pads...obviously.
Slotted on a previously-owned Mini JCW kept glaze off of the pads, so they didn't squeal. Slots probably wear the pads out quicker though...but I hated the squeal I was getting. Preventing squeal is the only reason I'd put slotted on a truck.
On my current Mini JCW with different pads and much larger rotors, I replaced the original solid rotors with solid Zimmerman rotors. No squeal on this setup...so I'm glad I didn't put slotted on this car.
Slotted on a previously-owned Mini JCW kept glaze off of the pads, so they didn't squeal. Slots probably wear the pads out quicker though...but I hated the squeal I was getting. Preventing squeal is the only reason I'd put slotted on a truck.
On my current Mini JCW with different pads and much larger rotors, I replaced the original solid rotors with solid Zimmerman rotors. No squeal on this setup...so I'm glad I didn't put slotted on this car.
Don't use drilled or slotted rotors. They're actually worse due to uneven heat and stress concentrations, lots of cracked rotors 
The only "drilled" rotors worth using are certain OE rotors, or the aftermarket DBA rotors, but they're all $200+ each!
The only "drilled" rotors worth using are certain OE rotors, or the aftermarket DBA rotors, but they're all $200+ each!
edyvw
$50 site donor 2025
Yes. I would be careful about the manufacturer. Brembo? Yes. ATE? Yes etc. DFC? No.
And I have DFC rotors on the back of BMW as that is the only one remotely affordable for my brake upgrade. They are dimpled and slotted. Why? That is how this rotor comes from the factory (drilled and slotted), but DFC offered dimpled and slotted. Kudos for not drilling. So, in front, I had to put my pride and run also dimpled and slotted Zimmerman as it would look weird.
But if I could find a plain rotor for rear, I would absolutely run that, and I track this car.
Here is a plain rear rotor on BMW before upgrade, Pagid (OEM on Porsche, etc.) for $35 a piece, after running whole day on the track including a 1 1/2hrs session without stopping. I went through brand new set of race pads in the back. Completely gone after that day. You can see a change in color due to heat. Those rotors kept going on for the next 30k on street and track:
Pass unless the rotors are larger than stock. Lighter rotors cool off faster because they have less thermal mass. This allows for repeated hard braking like you'd see on a race track. Solid rotors carry too much heat from braking zone to braking zone
Nah you are out on thin ice.
Light rotors overheats faster. Cant hold enough heat.
Lots of heat generated when you brake.
Blank rotors are still vented, if they aren't upgrade to vented.
