I don't know how. Pepsi is clearly the better choice. It tastes better and I think it's made with better stuff. I don't know. I'm just not fond of Coke.
I personally don't like drinking pop! It's not good for your body and if you drink too much you'll get blocked arteries! But I guess once in a while isn't going to do any harm. I prefer drinking juice instead!
Mostly I drink Dr. Pepper. That is, if I drink pop at all. I've switched to tea and water, but occasionally I will drink pop.
If I had to choose, I would drink Pepsi. Why? Because, like Sweet_Kandi said, it makes my teeth feel gritty. Known fact: Coke can dissolve a penny in 24-48 hourse. Coke has a strange, yet drinkable acid in it. Over the years it causes horrible cavities and other bodily disfunctions. And yes, Coke did used to have a form of cocaine in it, but they replaced it with another (legal) ingredient.