I don't turn the rotors on my car because I don't think it is completely necessary and the rotors are so soft that they would be at minimum thickness after 1 set of pads and being turned.
I just leave the rotors alone and stick new pads on them when i put in new barkes, and put in new rotors every other set of pads. With the front rotors on my C280, they have already worn beyond minimum thickness with the 2nd set of pads on them still at 50% thickness. If they had been turned, I don't think they would make it through 2 sets of pads. That is just my opinion.
1999 Dodge Ram 2500 Cummins Diesel
2002 Harley-Davidson Fatboy
Merlin Extralight w/ Campy Record