hello i have a 1996 f150 xlt extended cab 2x4 with the 5.0 v8 and automatic transmission with overdrive over the last maybe 3 months i have noticed that my mpg has begun to slowly drop. when i first bought it with 79k miles on it, i was getting around 18-20 on the freeway. now after i hit around 96k miles it started dropping to around 12. my driving habits are the same as before and i always keep up the oil changes and all that. recently changed the fuel filter about 1k miles ago. was just wondering if there is anything i should check or try.

 

someone recently told me that the increase of ethanol in gas is hurting gas mileage, but again, that is only what someone told me.

 

plugs, coil, wires been replaced? That's the first thing I would check

 

oh yes i forgot to mention that i did change the coil plugs and wires about a year ago now. i also heard the same about the gas but i never heard any real proof of it.

 

Well it is a fact the ethanol will decrease mpg's, but the levels are still fairly low. However I heard there's going to be higher percentage ethanol fuel pumps at select gas stations and more over the years for all the newer "flex fuel" vehicles.

I would suggest checking the trans and rear diff fluids and maybe flushing them, you might want to consider replacing or cleaning the fuel injectors, o2 sensor, cleaning the intake and other general maintenance. I saw a 1 mpg increase just in replacing the o2 sensor, and my old one was still working. But they don't work as well as they get older.

 

According to http://www.ehow.com/facts_5882696_ef...s-mileage.html and their referencing of the EPA, "E85, for instance, reduces fuel economy by 7 to 8 miles per gallon when compared to gasoline, according to the Environmental Protection Agency."

 

but can you run E85 in a stock engine? I would think you would know if you were pumping E85 and not regular

 

You can't run straight ethanol in a stock engine. The new flex fuel motors can though. But all gas now has small amounts of ethanol blended in.

 

Anything internal combustion, A "Seafoam'" treatment will help. Then, Lucas injector cleaner every 4-5 tanks. Buy the Lucas in Qt. size. It comes out to about $2/treatment. $5.99 otherwise.
See link: https://www.f150forum.com/f33/how-se...-1991-a-31505/

Also pick up one of these & use it!
http://www.handsontools.com/Equus-In...ol_p_5574.html

Working or not, replace o2 every 60K miles.

Although not accurate, every time I hear "ethanol" I picture trying to run corn syrup though injectors. It actually has more to do w/ combustion properties...or the lack thereof.

 

I do like my little scanner, I have it with the extension cable so I can sit in my cab and rev engine when required and what not.