I have an 87 F150 with the 302, long bed, extended cab, automatic w/overdrive.
What kind of mileage should I be expecting to get.
Thanks
SKy

 

Same yr. & model as you w/89K. I get 23 mpg @ 65mph. After an Ignition system upgrade, allowing a plug gap stretch to.056. & further base time advance to 16BTDC. a K&N drop in air filter & switched all fluids to synthetic. Still 87 octane.http://fullsizebronco.com/forum/show...ht=timing+bump

 

this truck has 300+K and I am getting about 10mpg. I need to do some work it looks like.
Thanks
Sky

 

I would start w/ Error code scans. http://www.handsontools.com/Equus-In...ol_p_5574.html And treat w/ a can of seafoam. http://www.f150forum.com/f33/how-sea...-1991-a-31505/ Many times 10 mpg is the magic number that implies a bad ECT sensor. E/C scans will tell. You aren't going to get 23 mpg out of the old girl, but !5mpg (50% increase) is easily doable, My truck got 9 mpg & would only do 65mpg downhill when I got it 5 yrs. ago.

 

The best I have gotten with my 94 is just shy of 14 mpg, and that's with a K&N exhaust, ignition upgrade and such. No codes and no issues in how it runs. 23 mpg is crazy. Wish I could get close to that. When I first got mine it was around 9-10 mpg.

 

before lift with the 302, i averaged 14 to 18 mpg at 70/75 mph. after lift i averaged 12.5 mph at 70 mph. with the 351, 13 mpg at 70 mph.

 

I flushed the radiator/block, installed a 180F thermostat, went distilled/antifreeze. Transtuned tranny, drained, went Synthetic. Flushed brake fluid, went Synth. Seafoamed (full treatment) engine, flushed, went Synth. w/ 20% Lucas Synth. stabilizer. Transtuned Diff., went Synth. Transtuned P/S, flushed,drained, went Synth. K& N drop in air filter.

Then, bought a Code reader http://www.handsontools.com/Equus-In...ol_p_5574.html , ID'ed active error codes, Replaced ECT, ACT & o2 (replace before 60k/ I replace mine @ 30K). Replaced 2 Cat system w/ single hi-capacity Cat & full flow glass pack. Removed, cleaned, reinstalled IAC, EGR. Checked Fuel pressure & bleed down. Replaced Fuel filter. Compression tested, Dry/wet bleed down (178-182 psi).

Then Ignition sys. upgrade w/ timing bump & gap stretch (10BTDC to 16 BTDC & .044 gap to .56 gap).http://fullsizebronco.com/forum/show...ht=timing+bump ..........Then, went sidegap at .054. http://www.performanceunlimited.com/...degapping.html That is all!

Also, changed it's diet from 91 octane to 87. There is a purposeful order to how it was done. Watch tire pressure & fight temptation to increase tire size & also Lift equals Drag.

Now the truck is reliable to the point of monotony @ 89K miles. Currently, I Seafoam the Combustion chambers only, before I change oil, every 8K & toss in a bottle of Lucas injector cleaner every 4-6 tanks. I leave my code reader hooked up under the hood & press "Test" every once in a while for the heck of it. My background is as a Commercial/ industrial machine tech so my method & procedure leans that direction. "Give it what it needs & it'll do what it's supposed to, well & w/ monotonous dependability".