I used to own a traditional Fast & Furious 1996 Honda Civic. And surprisingly many of the mods I made in the past to make it fast or look cooler, are the base for my increase in fuel economy.
I added a Tokico Illumina adjustable suspension almost 10 years ago, the mod makes my car lower to the ground (about a 2″ drop) and more aerodynamic.
I added a AEM Cold Air intake a while back, which pulls cooler air into your engine. From a performance stand point the thought is the cooler the air going in the faster the vehicle. But I think it does make my engine run more efficiently.
I really wanted to make sure the air going in was going out just as fast so I added DC Sports 4-2-1 Header and single piece exhaust from the CAT back.
To reduce weight in my car, I removed my passenger front seat (50lbs), sub-woofer (80lbs) and my spare tire(20lbs) (Update: I put the spare back, as even though I have never used it, it’s nice to have) with hopes to increase my fuel economy.