Did you know that Coca-Cola has less caffeine than either Pepsi or Diet Pepsi, but that Diet Coke has more caffeine than any of those (by at least 8 mg/12 oz)? As does Dr Pepper, which has a few mg less than Diet Coke; and as commonly known, Mountain Dew has all those beat. As might be expected, generic brands tend to have really sucky caffeine content (12.7 mg/12 oz for Sam’s Cola)