Originally Posted by Teutonaddict

I think you're lending too much creedence to what your SA is telling you. BMW rotors need only be replaced when their thickness falls below the specification stamped on the rotor hat.

While typically you might find rotor thickness falling below spec after two or more pad changes--you can bet the $tealership is gonna try to sell you rotors with each and every pad change.** It's not necessary.

In fact, many racers will tell you not to install new rotors and pads at the same time; it can make it more difficult to bed both components.

Spend $40 on a caliper micrometer and check for yourself, and you'll never have to rely on the man behind the counter again.

** This applies only after warranty expires and you begin to pay the frieght. You can bet that BMWNA does NOT replace rotors with every pad change when it's on their dime (e.g., within the 4/50 Full Maintenance Plan). Check your work orders!