I don't think so. The 'zero' has one slightly different ingredient in it to to the 'diet', but essentially they are the same drink (ie low calorie). I believe the reasoning behind the 'zero' drink is for the male market - diet drinks being a bit too 'girly' for big macho men!! :o)
definately different taste tho'- I've drunk Diet Coke for years and tried Coke Zero expecting it to taste the same or not as nice. I now unexpectedly prefer Coke Zero.
coke zero is awful!!! i drink diet coke like water and i tried coke zero and hated it. it tastes like full fat coke to me which i dont like, but i'm sure loads do!!
I think Coke Zero is supposed to be the same thing as Pepsi Max, I like Pepsi Max and don't find it citrussy - unless it's the one with lemon/ lime in it!!
I have tried Zero and while it seems to be better than diet, I still get an aftertaste of sacherine. I am afraid I love the full fat version which is why I don't drink too much!