so i don't know much about bmws mechanic wise, i do know that they can be expensive on gas and difficult to fix sometimes. I have always loved bmws and i am particularly IN LOVE with the 5 series. Im planning on saving up for one within the years of 2005-2008. I am confused though and which one i should get. I love the 530i (its so beautiful interior and exterior) but i don't know the difference between the other models. since i don't know the differences between the models, I'm clueless on the little things like how much gas it takes per mile or what type of gas i should use (i assume super high premium, my dad has a Mercedes and thats what he uses). If someone can give me some information on the different 5 series models i would appreciate it so much. Also, I'm not familiar with big mechanic words so simple language would be much appreciated.