What do I need and how do I measure my rotors to see if they need to be replaced. I have a 2001 996 c2. I've tracked my car probably 15 times over the last 3 years. No cracks anywhere on the rotors. Thanks

Ken

 

Unless there are significant grooves on the ext or int surface you should be ok. If you do need to, it's an easy DIY.

 

You will need a micrometer or a vernier caliper if you want to measure the thickness of your rotors. To do this, jack the car up at one wheel, pull the wheel off, and use the micrometer/vernier caliper to measure the thickness of the rotor. Make sure the points on the micrometer/vernier are flush and even on each side of the rotor or your readings will be erroneus. Also, try to take the reading at the center of the rotor. Take the reading and compare it with Porsche specs. If the rotors are too thin, you may want to consider replacing them.