I'm thinking about getting a ride for my friend and drinking his beer.
What would compel you to get rides from your friend and take his beer?
My friend is a total freeloader. I bet he'd do the same to me.
Just because your friend would take advantage of you by asking for rides and taking your beer, that doesn't make it correct for you to do the same to him. Take turns driving and share things together.
It's my friend, he has my back.
It's fine if you want to get a ride and drink your friend's beer, but make sure you let him know that you'll pay him back. Good friendships require a give-and-take, and if there's more taking than giving then your friendship will be unbalanced. If your friend knows that you'll pay him back, then he won't feel taken advantage of.