Their website says the serving size (8 oz.) contains 7g
sugar and 25 calories, and a full 20 oz. bottle has 17g
sugar and 70 calories. G2, as I understood the advertising, is reduced calorie (reduced sugar), with approximately half the calories/sugar of regular gatorade. Powerade makes the sugar-free calorie-free sports drink, Powerade Zero (that I think halbashes mentioned above). Someone please correct me if I'm wrong.
http://www.pepsiproductfacts.com/infobycategory.