Thx, I see what you mean and I think I have it right now. The tire looks rounder too, now. I might also make the side a little less round, but I can't seem to do that with the scale tool (select the part of the side i want to push inwart on both sides and scale in top view doesn't work).
Hmm, could you just give a hint on that 'particular way', I think I know what you are talking about. Anyways, I'm a quick learner (Nederlanders zijn dat over het algemeen, toch?

).
Thx!