Boosting MPG

[mrtinrs]

I have a stock 2003 Olds Alero. Haven't done anything to engine, tranny or exhaust. My main goal to boost fuel mileage. Also boost horsepower as long as MPG is not sacrificed. I will entertain any suggestions.
Thanks guys... One Deployed Soldier

[Medz]

as far as i know there isn't to much you can do that would give you gains in both ways, its usually one of the other. overdrive pullys (just smaller pullys for all the belt, ac/power steiring/water pump.) i don't know if you car has a belt drived fan if so you could get a electic fan, and also on the note electic water pump, they both would free up some drag on the engine, giving to hp and mpg. cold air intake would give a little of both, but i would most likely be so little you would notice, but over years that little bit would add up. new spark system, better plugs/wires, high volt coil packs. and free up you exhaust i don't know if they make headers for you engine but if they don't even get a cat back system. and if want to drop some money in to it, look in to getting you heads shaved, this will boost you compression rate and not cause more gas use. and look into a msd box. they have a website on the net just search them. other then that you can look into an engine swap they may have a engine with better hp and mpg but that could use up a lot of money. but yea usually when you get more hp you use more gas, so they don't usually go hand and hand, and this things will help out but i will not turn you car into a drag car, or get the mpg of a hybird.