I live in TN and practically everybody down here calls it coke. Even if if its mountain dew, sprite, pepsi, etc. The only time we dont do that is if we are at a restaraunt or if we are asking somebody to go buy us a drink. Examlpe Conversation:
Person 1 (from north): I have a headache. I havent had any caffeine all day.
Person 2 (from South): Then go buy a coke or somethin!
Person 1: I don't like coke. BUt I'll go buy a Mountain Dew
Person 2: Thats what I said! Go buy a coke!
Person 1: I already told you, I dont like coke!
yep... true story. This went on for like 10 minutes before I finally realized that the girl I was talking to called everything soda.