'96 F150 4.9L with the 5spd manual. I have added K&N air filter, Flowmaster cat- back exhaust and a Hayden electric fan. I am getting 15-17 mpg on the highway driving approx. 86 mi. per day, as long as I don't exceed 70 mph. I have found my best mpg is @ about 68mph. I am considering going with an after market cam but was told i'd be better off going with a computer tuner for optimum results. Any ideas?? Would sure like to see 20 mpg @ 75-80 mph...lol

 

Honda Civic??? I went through my truck and trashed all the stuff that I was carrying in the bed that I didn't need. I could tell a difference. Now the only thing back there is my new exhaust that fell/scraped off while 4x4ing the other day.

 

you are dreaming, no way 20 mpg at that speed.

 

You gotta dream, thats what makes the world go around!!

 

haha.. our minivan doesn't even get 20 MPGs at 80 MPH...

What frederic does is pushes the clutch in going down hills on the highway in order to acheive highway speeds at idle RPMs

 

What is your differential gear ratio? Mine is 2.73, I can get up to 20 mpg at 70MPH.

 

ok, i will put it this way, you will never get 20 mpg going 70 mph in your truck, ever.

maybe that was more realistic for you.

and if you say you do i do not believe you.

 

I agree with quicklook2, there is NO way you can do that, im running a 5.8L and getting 12 mpg on street, 14ish on highway.

 

I am running a 95 4.9L 2wd with the 5 spd manual, the best I have done on the highway is 25 in the slipstream of a semi, normally I can run 65mph and get 20-22 mpg. That is with a lund sunvisor and bug shield. I have a walker downpipe and custom y'ed dual exhaust.

 

I get the best mpg when I shift into netrual and hoist my sail. Gotta look out for those 18wheelers though.....their draft can REALLY screw your sail up.

 

You might consider using a TB spacer. Some in the Mustang forums have reported an extra MPG. Also, underdrive pullies might help a little in that they will help free up some HP and thereby get another MPG if you're lucky.

A decent tuneup and chip, like was mentioned, would be a must, as would be possibly switching to a synthetic oil. Other than that, larger tires - hehe!

 

curious on that note... why is it illegal in some places to do that?

 

only in automatics...

 

yes, I was thinking about that and you can't stop somebody from doing it on a manual.

Perhaps its for safety reasons... if your tranny is in neutral, there is no way you can instantly apply power to the wheels (you'd have to shift). you can stop, but sometimes it is in fact safer to speed up.

My thoughts on it anyway

 

I follow all of the old fashioned guidelines regarding tire pressures, alignments and tuneups, and I do run synthetic oil and a K&N Filter. I have a five speed and a 3.08 rear gear. My consistent best from several statewide jaunts is 19.4 mpg. Usually about 65 mph