Dear Wizzard351,

You are not either getting 28mpg in your F100 with 300 and no overdrive! I had a similar '85 model and got 16. Now I have a '69 with 240 and get 17. Are you talking about all downhill?

I'll believe you when you post raw numbers.



P.S. Just in case you really do get 28, you are the man!

 

I sold my 1985 F-150 with a 5.0 L and bought a 2002 Focus with a 2.0L Zetec.

-Matt

 

Keep a constant speed (use cruise control if you have it!), minimize a/c use, and accelerate slowly and smoothly (in other words, avoid jackrabbit starts). Doing this, I made my 1992 Bronco Eddie Bauer 302 get 18.5mpg on steady freeway, and about 12 in town. This in a truck rated for 17mpg freeway. Then, as others have said, keep tires properly inflated, make sure the wheel bearings roll freely, and if you have a pickup, try and keep the tailgate down (or is that an old wives' tale? Makes sense to me, that thing is a big wall for the air to hit...).

 

Clutch the downhills in neutral, the engine goes back to an idle speed, and starts sipping fuel.

 

I thought I read somewhere that shedding 400lbs is equivalent to increasing 1mpg. Don't know how this is calculated or whether it's just some urban legend, but it makes sense.

With that said, driving on an empty tank should help mileage also. Think of it... that 30gallon gas tank weighs almost 200lbs when full! That's worth 1/2mpg. LOL

 

I've thought about that, I usually drive under a half tank...and most of that time under a quarter...although I didn't really start doin it for that reason.

 

I think that it was on this site that I read an article about lowering the tailgate and its DECREASE of gas mileage. The theory is that if the tailgate is up, the bed fills with air and creates a sort of "ghost tonneau". With that done, the air flowing up over the cab doesn't flow down into the bed and create downpressure. If the tailgate is down, there is nothing to hold the air, hence downpressure. If I remember correctly, driving with the tailgate in a spoiler position (1/2 way down) was supposed to increase mileage though. For myself, mostly what the other guys do, air pressure, keep my foot out of it.

 

I repaired my vacuum advance on my distributer and changed my plugs about a 4mpg difference.

 

Get a tonneau cover, added 2.5 mpg on a 1997 f150 Ext. Cab 4.6-- I get 20 mpg wiht it

 

Thats funny you should mention that one. My truck actually goes faster in nuetral down certain hills in my area, than I could comfortably go in gear.

 

Cycling taught me a lot about energy conservation. Roll a hill or dip just right and it takes minimal energy, speeding up on the down and maintaining average pedal to roll up the other side just like on the bike has got to be easier on fuel. Granted you vary in speed, but it works.

The flip side of that is Cruise Controls - CC is fine for long flat stretches, but it pitches your mileage right out the window in mountains and hills! Ever notice how hard the engine runs to get to speed with cruise set? Combine that with the braking action and the exact opposite of the above method is produced. NIX on the cruise control in hilly areas.

 

yeah but greywolf, a bike might have 21 gears, and my truck has 3
:-)

what I couldn't do with a 7.3 Idi and 21 gears, well errr I mean aside from shift alot.

 

Okay, I've been trying all the tricks y'all have come up with, plus some. The biggest difference seems to have come with slowing down to 55 mph. Most of my driving is in the 7 miles from home to town, speed limit 65. I only lose a few seconds by slowing down to 55, but I think it's really kicking up the mpg. I've gone from about 17 to my latest fill-up at 18.9 mpg!

I tried adding acetone for one tank a few months ago (did you follow that thread?), but I didn't notice any difference.

I get to take her out on a road trip in a couple weeks. I'm going to try everything, and perhaps get the golden 20 mpg!

 

how much acetone did you add

 

In my 1995 Explorer 4.0 v-6 4x4, it has an "information center" in the middle and tells current MPG, and average MPG. I tried several different things over the past 6 months. The greatest difference came from "timing" the traffic lights. 1 year ago, I would have thought "whatever" about this. But having to learn this skill when I started driving the 18 wheeler ( 1yr, 2 months ago) I have now applied it to my driving habits in my little truck. AND IT WORKS!!
first 2 fuel tanks driving "old style (ie. stoping at every red light)" 16.5mpg av. " New style ( wathching ltraffic lights and stoping as little as possible)" on the next 2 tanks was 18.2mpg av. Now I have changed the air filter to K&N, used full synthetics, and get close to 19 every time.
PS: I also have oversized 275/70/16 All Terrain tires!