I’ve replaced my rotors last year due to cracks extending over 7mm from holes. Guess what, with only 20K miles on my car since then the cracks are reappearing -2 to 3mm for now. Car was driven moderately. What are you guys getting? I was told 55K miles before any cracks to be the norm...

 

they are normal at that size dont worry about them. must admit I do run a slotted two piece front rotor these days as do most of the racers.

 

I would think it would be totally dependant upon driving style,
number of track events, etc.

If you run your car up to 150 mph + regularily AND slow it down QUICKLY
so as not to endanger others...then you will go thru rotors quickly, even
though you are only "street driving"

good luck

 

I only get 6 to 8 weekends out of a set, but that almost all track work.

 

About 6 track days for me! Thats why I am switching to floating 2 piece rotors (PFC) as soon as they come out.