I bought a 08 civic about three months ago as a commuter and am wondering if there are any parts that I can purchase and install to improve my gas mileage on it?

Any Ideas

 

welcome to the forum, before you do any mod's to your new civic, ask your dealership service dept what will happen when you install your mod's to the warranty. My dealership said if I purchase the mod item and they install it, they will honor if anything breaks. Once the warranty is up, I can put in/on anything I want to. Some dealers will say go put it in, let us inspect it and give you their blessings.
Cold intake and complete exhaust systems are the first items ( engine breathing ) Don't have a lead foot!! keep the car clean and polished at all times. tire pressure at 35 psi