I used to not differentiate between them, but for some reason, used to ask for "Coke", in the general hope that I would get a black, carbonated drink, without any hassle. For some reason, everybody before McDonalds were able to accomodate me, but THEY insisted on telling mje they had one but not the other. *sigh* Coke or Pepsi, I don't care. Sugar free though, I will take Pepsi Max (if available), over Diet Coke, because the former tastes better to me. Somehow, Pepsi Max got a reputation for exploding in fridges, so it is quite hard to find someone stocking Pepsi Max near me.