mods for mpg?
 

with the gas crunch this summer, thought it'd be nice if we have a list of mods and maintenance items thatll increase mpg.

i know these work for sure:
air filter/ intake
electric fans
fuel filter

but how about...
grounding wires
ignition wires

any others?

a complete tune up

Try keeping your throttle foot FARTHER AWAY from the firewall, not closer to it.

Less macho revs at stoplights. Nobody cares anyways.

Check your tire pressure.

All free mods.

HIGH FLOW CAT
CAT BACK EXHAUST
4-2-1 performance header
All these items cause less back pressure, less back pressure makes for less load and more power. They do increase MPG.
Other mods that will increase MPG are
ALUMINUM FLYWHEEL
ALUMINUM DRIVE SHAFT
These items reduce LOAD, just as an electric fan swap does.
SAFC can get you better gas mileage when tuned with a wideband o2 you can tune for leaner ratio's using less fuel and not sacrificing power
S15 HLSD has a wider gear ratio that will overall conserve fuel compared to the stock open, or stock VLSD diffs.
Iridium spark plugs increase ignition spark and last up to 90,000 miles before next tune up.

Modifications that decrease fuel economy.
Advanced timing
under inflated tires
retarding cams
egr block off

Removing your spare tire, jack, and anything heavy and unnecessary that you are hauling around.