Brake Rotor Thickness

[spaxz]

Hello,
I had new rubber installed on my 2006 A4 Quattro today. The Mechanic mentioned the front brakes are gone and the back are pretty close to being done. He also mentioned on Audi's, the pads and rotors are to be changed together. The consensus online seems to be the rotors do not need to be changed unless they are too thin.

Mine do not have grooves in the face of the rotor (are smooth) but the edge of the rotors have lip on them. The car has 176,000 km on it. I purchased it with 170,000 km so I'm unsure if they have been replaced prior - I'm assuming the pads have been changed before with that many kms on it?

What is the thickness the rotors need to be in order to determine if they are still good?

[marlboro]

Audi official specification allows only for 1mm wear on each side of the rotors. If they are worn more than 2mm in total from the original thickness, they have to be replaced.

[mtroxel]

He also mentioned on Audi's, the pads and rotors are to be changed together.

Total crap. I've done brakes jobs on my Audis for about 25 years. I've always swapped rotors every other set of brake pads. I never turn the rotors, even if there's some grooving. The worst that would happen is that the rotors would start warping, I'd feel it in the brake pedal, then decide how much it bothers me. And I've never had a set warp. But when I do swap rotors, I always buy OEM.