0 camber is a bit weird, on track you'll burn up tires really fast on the outside edges this way. The only time 0 works best is driving in a straight line. You can run 0 toe and this will reduce tire wear.
A conservative camber with street tires I would say is -1.0F, -1.4R, no less. More aggressive would be -1.8F, 1.6R, the front camber in particular helps reduce turn in under-steer. On race tires I run -3.5F, -2.0R and I still cook the outside edges of the front tires before anything else.
Was this Nordschleife? I hope to get to run there some day. Definitely a very high speed circuit with some challenging corners thrown in. On the circuits with more time in corners than straights I'm usually the one hounding the GT3's
