I guess I’ll be the iconoclast and say that drilled and/or slotted rotors do work better in some circumstances.
I’ve got drilled rotors on my Mercedes, the 2002 V70XC and the 2001 V70 T5. Better brake cooling under hard use was the intent, but what I notice is quicker bite in the rain and in slushy/snowy conditions where moisture gets on the rotors*. There is a path for the water to be squeezed out. No weird noises. No cracking. Long life. All good.
I’ve got slotted rotors on the 2002 V70 T5. Yep. Weird whoosh noise under heavy braking, but again, in wet, particularly, freezing wet, there is better initial bite. Also, and I didn’t expect this, longer rotor and pad life. I got 100,000 miles out of my first set of front slotted rotors. The slots allow the pads to stay clean, and avoid embedding tiny bit of debris. Very smooth, even wear was the result.
I liked them so much, I bought another set for the car.
For the performance increase in adverse conditions, and the critical safety difference, with long life and even wear, I’ll have slotted or drilled rotors on every car.
*Many years ago, as I was driving on I-91 in rain/sleet, in my 1985 Volvo 245 Turbo, I braked for an exit...and ZERO brakes. Despite good pedal pressure, no deceleration whatsoever. The rotors had iced up as they were right below freezing with liquid moisture in the air. I had no brakes. I skipped that exit, drove ten miles to the next one, while pressing the brakes. Several applications later, I had melted the ice film, and had good brakes again. I applied the brakes periodically for the rest of the drive, until the weather had changed completely to snow.
I’ve got drilled rotors on my Mercedes, the 2002 V70XC and the 2001 V70 T5. Better brake cooling under hard use was the intent, but what I notice is quicker bite in the rain and in slushy/snowy conditions where moisture gets on the rotors*. There is a path for the water to be squeezed out. No weird noises. No cracking. Long life. All good.
I’ve got slotted rotors on the 2002 V70 T5. Yep. Weird whoosh noise under heavy braking, but again, in wet, particularly, freezing wet, there is better initial bite. Also, and I didn’t expect this, longer rotor and pad life. I got 100,000 miles out of my first set of front slotted rotors. The slots allow the pads to stay clean, and avoid embedding tiny bit of debris. Very smooth, even wear was the result.
I liked them so much, I bought another set for the car.
For the performance increase in adverse conditions, and the critical safety difference, with long life and even wear, I’ll have slotted or drilled rotors on every car.
*Many years ago, as I was driving on I-91 in rain/sleet, in my 1985 Volvo 245 Turbo, I braked for an exit...and ZERO brakes. Despite good pedal pressure, no deceleration whatsoever. The rotors had iced up as they were right below freezing with liquid moisture in the air. I had no brakes. I skipped that exit, drove ten miles to the next one, while pressing the brakes. Several applications later, I had melted the ice film, and had good brakes again. I applied the brakes periodically for the rest of the drive, until the weather had changed completely to snow.