Holly (my daughter) did an experiment for her middle school science project about "Which Soda Fizzed the Longest".
We had Diet Pepsi, Coke, 7UP, Dr Pepper, and A&W Root Beer if we remember correctly (asking my wife right now) and the Diet Pepsi won by a land slide!!
I do not drink hardly any carbonated drinks at all, maybe 4 or 5 a year if that many. But my wife and daughter tear into Diet Pepsi like I do Iced Tea!
Billy