need better mpg
Thread Starter
Senior Member
Joined: Apr 2010
Posts: 154
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need better mpg
i have a 1991 ford F150 with the 4.9l and i am wondering how to get better gas mileage...right now I'm getting around 12-13 at the best but i don't think i want to do a aftermarket intake what are some of my options. also i put new wires and plugs on it about half a year ago so that is outta the way.
would seafoaming it do anything?
would seafoaming it do anything?
Senior Member
Joined: Jul 2007
Posts: 3,806
Likes: 480
From: Cape Girardeau MO
Keep in mind the 4.9L is essentially a tractor engine - very very good at what it was designed for - which wasn't fuel economy.
Best advice I can offer is to drive it like your grandmother would.
Best advice I can offer is to drive it like your grandmother would.
Springer Spaniels Rule
Joined: Jun 2009
Posts: 3,445
Likes: 17
From: Milltown, NJ
No, any advertised significant mileage boost is a myth it will give a little more power, but you will only see mileage under perfect highway conditions. Mileage is determined by how educated your foot is.
Senior Member
Joined: Jul 2008
Posts: 58,557
Likes: 1,165
From: Long Beach Calimexifornia
P/u a Haynes repair manual
Do error code scans & deal w/ any active codes. http://www.handsontools.com/Equus-In...ol_p_5574.html
Seafoam treat the engine https://www.f150forum.com/f33/how-se...-1991-a-31505/
Transtune treat the transmission
Switch to Synthetic fluids
K&N drop in air filter only, if not a MAF engine
Do this Ingition System upgrade Mod (includes stretching plug gap & further advance of base timing) http://fullsizebronco.com/forum/show...ht=timing+bump
Stick w/ 87 octane
Stock tires, properly inflated
Don't lift
Lucas Injector cleaner periodically
Conservative driving style.
Do error code scans & deal w/ any active codes. http://www.handsontools.com/Equus-In...ol_p_5574.html
Seafoam treat the engine https://www.f150forum.com/f33/how-se...-1991-a-31505/
Transtune treat the transmission
Switch to Synthetic fluids
K&N drop in air filter only, if not a MAF engine
Do this Ingition System upgrade Mod (includes stretching plug gap & further advance of base timing) http://fullsizebronco.com/forum/show...ht=timing+bump
Stick w/ 87 octane
Stock tires, properly inflated
Don't lift
Lucas Injector cleaner periodically
Conservative driving style.
Last edited by ymeski56; Dec 25, 2010 at 06:07 PM.
Wondertwin2
Joined: Dec 2010
Posts: 1,564
Likes: 0
From: Ohio
If not seafoaming it, then some lucas FI cleaner if the 4.9 is EFI. If you have a tonneau on, get rid of it. There's a vortex created in the bed of the truck that lets other air flow right over it, if you put a tonneau on, you're destroying that and destroying the mileage even more. Same with the mesh tailgates and whatnot. Dropping the truck would give more aerodynamics, but it would probably ruin the look, and going with the stock size tires instead of any aftermarket sizes you might have. Intakes probably won't help much, but if you had true dual exhaust it might.
Last edited by Mr.Distance; Dec 25, 2010 at 05:27 PM.
