[ATaylorRacing]

On a 98 Neon 5 speed that was rated at 41 mpg I did:

I removed the stock air filter assembly and put three layers of screen mesh over the throttlebody opening with a hose clamp....cost near 0, picked up right at 1.8 mpg, and also ran nearly .25 seconds quicker in the quarter. This put me at the 41 mpg that it was rated at on a 80 mile loop with top speed of 65 and 5 stop signs.

An underdrive pulley kit on the same loop and conditions put me up to 43 and again nearly .25 seconds quicker in the quarter mile. Cost was about $200.

On the same loop I would shut off the motor if I had a slower speed limit or stop ahead and got 46 mpg!

This car eventually ran 14.8 in the quarter on the motor and 12.17 at 117 with a 125 hp shot of nitrous!