Ecomod on Mercedez-Benz E320 Station Wagon
 

Hello to all!
I have just inherited a 1999 Mercedes-Benz E320 4-Matic station wagon, as my first car as I have just recieved my liscense.
My goal is to double the fuel efficiency it is currently gettin, because I don't even think it gets 20... and it only takes premium!!
I am buying a scan gage so I can see the MPG's I am getting, but I want to know of some modifications that I can make to get better MPG's. I will be taking of the emblem, and possibly getting a new grille, but I do not think this will about to much, and my mother (who is the owner of the vehicle) will not allow me to make any external modifications.
If anyone has any knowledge of how I can accomplish my goal, PLEASE LET ME KNOW!!!
My email is jamessilva17@gmail.com, so feel free to e-mail me.
thanks a lot

Which wheels do you have on it and is the exhaust stock?