When I was growing up in the South it was not odd to have an aunt or a friend or someone utter the words, "Let's go get a Coke". It didn't mean that I had to end up with a Coca~Cola product, either. In fact it was more likely that I'd end up with a Barq's, Nehi or other yummy bubbly beverage. My aunts would almost inevitably get an RC or Dr. Pepper. The fact that it was also pronounced "Cocola" made no difference, either. It was just what all soda water based drinks were (and likely still are) called in the South.
Well, the folks at The Pop vs. Soda Page have popped back up onto the radar again with their excellent map on the subject of what our favourite beverages are called by region. I was surprised to see that in my current region the Southern "Coke" is more common than Soda or Pop. Must have been an influx of Southerners into the region at some point in the past. Interesting.
Of course, where I grew up, if you wanted a Root Beer you asked for a Barq's. Just because it was the best on the market.
Soda, Pop, Coke, Root Beer