Any preferred brand also?

 

I'd say pads at 80% wear at the latest. OEM AP1 for street.
Rotors, when you can feel a lip with your finger or warping.
I'm liking the SOS ones right now.

Neither of these go by mileage/time IMO.

 

Like boofster said, lip on the rotors or low pad material, it's time to change 'em.

You can get OEM replacement blanks for $35 a pop. Combine this with good pads (Carbotech XP10) and good ducting and you will not have a problem chewing through rotors/pads.

 

It really depends on your driving style.

My OEM AP2 pads lasted 38K miles with about 5K of hard driving miles.

 

Timing/mileage has nothing to do with like the above posts. oem pads are good for street/spirited driving, I run the hp+ pads for the track/street as im too lazy to change them, work fine for both just squeak a bit on the street. because racecar!