I seem to be getting only around 15 - 16. It does seem to idle very fast at start up and that thingy on the left hand side of motor surrounding the exhaust manifold and tubed up to the air cleaner is gone due to deterioration. Also I do seem to have a lot of valve clatter. That 5th gear seems almost useless. Oh yeah and my brakes sometimes seem like I am playing russian roulette (intermittent air pressure to booster, not sure why).

 

sometimes if you hit the rear brakes and they go really low then on the second time they grab could be due to unadjusted rear brakes. i have a 85 with the same set up and i used to do a 80 mile round trip with just a bit over a quarter of a tank used, i dont really know my gas tank size. if your air emissions stuff is all rotted off take off the air pump that might save you a hair of mpg.

 

So a little over 1/4 would be about what I am getting. That SUX in my opinion. What is the purpose of a smaller engine if MPG is worse than the larger 4.3 engine ? I also got an F150 with 5.0 and same crap. I get 12 MPG and a 5.7 gets 18 MPG. It should be illegal for these mfrs to do this.

Where is the AIR PUMP btw and what is "a hair" ?

BRAKES - my problem, IMO seems to be air pressure to the booster ( which I replaced already ). Stop and go traffic is the worst.

 

I got the 2.8L V6 with 4 speed auto, and I agree with what your saying about 5th gear, although mine is the overdrive gear. When I just start to go up the slightest incline on the interstate (55-65MPH) The truck starts to bog down. It accelerates better in 3rd gear with the same throttle depression. I get about 16 17 in the city and nothing better then 20 highway. My mechanic called my engine anemic.

 

if your looking at the front of the engine the air pump will be located at the bottom left. i took mine off cause it was making all sorts of weird noise. but if you have a serpentine belt you might not be able to bypass it

my truck is beat to crap i dont even know how its still running. in fact i dont even drive it anymore cause its practically unsafe due to a rotted body but with modern technology and fuel injection they are able to get way more mpg now. kinda like how 4 cylinders now make as much horsepower as a v8 did 20 years ago