Just a thought for most of us
 

I have been trying to pick out the mods that will help most people most of the time and i have come up with these (because not all cars have lean burn and so forth). and some people don't have a lot of money.

(in no particular order)

Higher air pressure in tires

if possible tuck your wipers into your hood or make them park lower

keep your car tuned up

grille plug

air dam/front bumper mod

wheel skirts

belly pan

SLOW DOWN!!

coast when possible, sometimes you can coast where you least expect it.( i can coast up two hills and into town, a total of about 1.4 miles without ever touching the gas!!!

remove extra outside features

smooth wheel covers

bed cover/shell for those trucks out there

less restrictive air filter (they do work) i put one in my moms dodge grand caravan and her mileage went from 16 to 24.5!! i can get 31 AVERAGE in it.
and you don't have to keep buying new filters all the time $$$$$$$!!!!

don't use your A/C as much (when you have small kids it is sometimes needed)

choose routes carefully, just cuz its shorter doesnt mean its more mpg friendly. 15 miles through slow down/speed up or 18.8 miles of highway(chances are you will use less gas on the 18.8 miles!!!

VACUUM GAUGE ( and actually use it!)

use thin, synthetic oil

EMPTY YOUR TRUNK!!!!!!!!!!!!

try to coast over small hills

and don't let others drive your car. and remember 1 mpg can cost you $3-$4!!

There are already a few permanent lists here.