how to get better gas milage?

[jimmy pisstank]

Im looking to get better gas milage out of my 1996 Chevy ext cab 4x4 5.7L. any ideas what I can do? not looking to do extencive engine work so mostly bolt on parts.

K&N filter and cold air intake?
New Chip in the computer?
Spacer between the throttle body and intake?

Anything else or any ideas or how the above should help?


more horsepower = easier to move vehicle
more horsepower = more gas

is this right?

Jimmy Pisstank

[Case 7230]

You will get plenty of replies on this one. If it was me I would go with free-flow exhaust and if high miles, new oxygen sensors.

[jimmy pisstank]

yeah, i plan to do the exhaust once i break the factory one but not untill then.

[brad4eva]

Since this is on the same subject as mileage , what about if i wanna do it more gas milage with a Carb ? what all would i have to do?

[heavychevy85]

i have 2002 yukon and it has over 280,000 on it dose that mean i need new oxygen sensors on it the check engine lights been on and the previous owner said it stayed on since it hit 100,000 he never had it checks and the inly thing they replaced on it was the rebuilt the tranny at 250,000

[brad4eva]

I would deffinately say you would need 2 replace oxygen sensor! lol 2002 280 grand?? thats aloota miles lol did u go to china and back 10000 times?

[stumpuller454]

Alright this has been hijacked a few times here but from my experience, the largest fuel economy gains are firstly go with a good flowing exhaust system, secondly the best improvement is a ECM reprogram, you can get hand-helds, they are pretty good, + you can remove them at any time BUT I STRONGLY recommend getting a custom ECM tune, IF all you require is all-out, mile-stretching fuel economy, a custom program can be set up using regular fuel 87or89, and can deliver 1mpg or better easily, and honestly no other bolt on (other than exhaust) is going to give you that much gain. ALSO speaking BEST (but not cheapest) fuel economy would be to get electric fans (easy 1mpg or better,...its true) and/or an electric water pump and a power pulley setup that decreases belt flex (the less turning a belt has to do the better)

Oh and the throttle body spacer IS a good paperweight... for MPI trucks, TBI trucks might see a minor tourque increase but fuel economy might not even be noticable...and a air intake and filter setup is usless unless your exhaust is modified first, and works very well with headers

Along with many other things my truck when new got 7mpg all the time it now gets 11mpg towing all time, as of right now i`ve never done a hwy trip so hwy mileage is unkown but it would be at least 2mpg better, now this may not sound good but its far better than 7mpg, my truck weighs 6500lbs empty, and can easily haul 11,000lbs i have gained over 5mpg over stock at this point and the engine is completley stock...its all bolt ons

[brad4eva]

Ok... listen heres whats going on with me, i went from all computer to like nothing cmoputer... on the ecm deal? wat would i have 2 do.. i mean can i still reprogram it and wat u mean by free flow exhaust , I just got straight pipes no cats or anything no O2 sensors

[stumpuller454]

well what exactley have you done? are you carburated? if so WHY? and as for the exhaust here is what i`ve experienced over stock, first replaced muffler and tailpipe, gained 100kms (60miles) per tank of fuel (totally the largest economy gain) BUT it was a flowmaster 50 series and the interior resonance gave me headaches, so ditched it for a good used 4" dynomax system (actually for a deisel) and there was no gain other than noise, THEN got full length headers, was good all around gain (but freakin expensive over 1k) and a much better exhaust note, not more than .5 mpg gain, THEn removed my cats, TOTALLY LOST BOTTOM END!!! *BUT* gained 1mpg or better fuel economy, so at this point they are still gone, I did notice a much greater top end power increase without cats, pulls my trailer like a freight train in 2nd gear up any hill at 65mph, which works out to nearly 4500rpm, but so much power there i could pull faster even! so kinda lookin at getting a cam with more bottom end tourque to bring the power range down abit...

What size are your straight pipes?

[heavychevy85]

will the motor run any better with the new oxygen sensor(s) adn i was lookiin in to getting the cat-back system from cherry bomb it sounds freakin sick on a 6.0 so it should sound just as good on my 5.3 and the k&n and i was lookin into electric fan(s) will a universal fan work from advanced auto or somthing they run around 87 bucks for one 16 inch fan