DrkShdw983 5/5/2011I have an 01 civic with an intake, sport flywheel, and underdrive crank pulley.. I get 36 - 38 mpg.. If you want to get better milage I highly recommend a short-ram performance intake. If you get more air into the engine it will be able to run leaner and use less fuel. you'll also get more power and more throttle response
safetybitz 1/6/2013I know this is an old question, but my 4.6L 2003 Mountaineer got increased mpg when I replaced the lugged tires with a more highway efficient design tread. Original MPG was 13-16 mpg and I now get 16-19. AWD all the time causes a lot of the reduction but I didn't need the off-road capability from lugged tires.