I was wondering how I can get better gas mileage out of my truck its a 1980 f150 300 6 cylinder I've got a 4 speed with overdrive with a 2.75 open rearend with 31 10.50 r15 tires I've been told run it really lean and I can get around 25 miles a gallon I just rebuilt the carter single barrel carb just too rule that out and I don't wanna automatic so I'm open too anything else I'm just curious as too what I can do

 

get a vacuum gauge and tune the idle mixture to max vacuum..( and then usually go a slight bit leaner at idle)
then tune the ignition timing to max vacuum...
then tune ??????? check the advanced (2.5k to 3k rpm) ignition timing

if you want to really really do good, get an air fuel ratio gauge 170 from Amazon and install it in the oxygen sensor port.


for MPG the best is to drive slow, and make sure the engine is proper air fuel ratio, and that ignition is occurring at the best time

 

I have no oxygen sensor port its an 1980 f150 and I tuned the carb after rebuild

 

How did you tune it? Also I am sure you could add an oxygen sensor port. Air/fuel ratios are really cheap compared to gasoline costs over a year or so.

Have you checked ignition timings?

What does the vacuum gauge say at idle?

 

Had a friend that owns a shop tune it after I rebuilt it also had compression test done

 

well he did a good job if it is 25miles per gallon. besides a vacuum gauge and air fuel ratio gauge there isn't much more you can possibly hope for or do on your own..

change the oil and make sure the filters are good and drive safe

 

I was also wondering if changing the piston rings and head for higher compression would help

 

If your willing to do that much work then do aero mods, air damn, bed cover, under pan.

 

you'd spend 2k dollars, and you might end up having to buy premium gasoline by the time you are finished

have you even done a compression test? if you are not burning tons of oil then you don't need new rings.

 

I don't burn any oil I just figured I'd replace them soon because they've never been replaced

 

Get rid of those big tires and that will help some. Less friction on the road. That's one of the first rules when building a EV. Skinny tires pumped up to the max.

You can also run synthetic oil in the tranny and the rearend.

The "take it easy" suggestion will work well also.

Here's a link to a site with a lot of ideas on the subject.

http://ecomodder.com/forum/showthrea...ehicle-83.html

 

Check alignment; correct tire air pressure; standard sized tires with non-aggressive tread tires; eliminate all unnecessary weight; make sure brakes are not dragging; check for correct choke operation; does the truck still have the factory air filter housing and the associated hoses [cold and warm air provision]?; remove bulky toolbox or driving lights, properly tuned, clean full sized air filter... etc.

Drive like an old man; short shift... get into the next higher gear as quickly as possible without lugging the engine. Cruise @ 55-62 mph.

"Pretend that there is an egg between your foot and the gas pedal."

1986 F150 w/ 4.9L, 4 speed manual O.D., 3.08 rear gears, Duraspark conversion, no EGR, catalytic convertors still intact plus driving as described above = 17 MPG in town and 22+ MPG highway.

Still working on making it even more efficient! [OK GTG 9/13/14]

 

If you are getting 25mpg I want to know the mpg of the truck pulling you. Seriously, I have never had a full size truck give me 25 mpg.

 

The OP said he had been told he can get 25 mpg.

 

You are right. I misread it.