Hmmm, wash your truck with hot water then dry it on the High setting in your dryer. It will shrink down to a Ranger size and you'll hit your target of 30mpg.

Seriously, I run a '76 with an edelbrock carb and intake mated to a E4OD automatic with 3.0 rear end. This drive train setup doubled my previous mpg that I was getting with the old 360/C6. Straight hiway I can get over 20mpg.
Mixed hwy/city I'm between 15-18mpg depending on how I drive which tends to be a little heavy footed at times. The 3.0 gear really sucks for city driving but keeps the rpms real low on the hwy. Almost too low as the engine is below it's better torque range so I have to kick it down to third when I get to a hill.
I had 30" tires on the truck initially and noticed a big improvement when I went to a standard LT235/75R15 tire.
I am considering a slightly higher rear end ratio and a better cold air induction set up. Likely do the air induction first as it's easier.
The new trucks don't get 30mpg and have a lot better technology not to mention aero-dynamics. 30mpg in one of these old trucks would take "radical" changes in weight reduction and aero-dfnamics. 25mpg is probably do-able but expect some compromises in drive-ability.
Good luck and keep us posted on your progress.

Frank

 

At our shop here in Gunnison, (7700) we have a few regulars who are always concerend about fuel mileage, here's what we've found: platinum catylists don't work, so don't waste the 100 bucks. On a 77 F-150, 400 c.i. 4spd 3:73 the customer consistantly gets 19mpg hwy. We put .82 jets in his 650 edelbrock, run the timing at 12 btdc, curved the distributor, MSD ingition firing the plugs at .060 gap, pink(wimpiest) rod springs, edlebrock performer intake, hotter thermostat valve and STOCK heads and exhaust manifolds. Another is a 72 F-100, 390, 4spd, 3:73 posi. We get 17 in that, with an almost identical setup but also included an MSD spark retarder, becaues the guy travels to denver alot, and it pings at 15 BTDC at lower elevetion. Carb is a holley though, and I wasn't there when we switched it over from the old 4100 ford that we put on it to begin with. 30 mpg is not impossible, It is just a matter of how bad you want to get that. If this is truely a quest like you've posted, think about increasing compression, knife edging, radiusing and polishig the crank, polish the passages in the heads, sealing off the heat riser under the carb, (lower plenum for your fi.) and Degreeing the cam up.Be sure that your knock sensor is operational before you go fooling around with spark advance though.

 

That brings up a good point, sending things like the head, or the exhaust headers, or even the intake manifold to get Extrude Honed is a good idea.

 

I've seen that link before. Not sure it counts. 1. It's not a car, it's a set of plans. Not even a kit car. 2. I don't think 17hp qualifies as a sports car. 3. Not sure I buy the idea that an engine is more efficient at 60%-90% of its rated horsepower. It's been my experience that the more power demanded from an engine, the more fuel it uses. 4. There is no verification that the designer actually reached his claim of 128mpg.

To be honest with you, I've never even heard of this thing before last month. If it really could do what was promised, I would expect to see these things all over the roads.

But again, look at the specs.
1200 poungs
17 hp
6 inches ground clearance

Light, low, and low power seems to be the recipe here. Go for it and good luck.

 

Collage level fuel effiency competitions are at the 2,000 mpg level.

But yes, light and effcient are the basic forumlea.

 

Im 53 years old and I remember the original article on this vehicle. If you look closely at the back of the "Centurion" you will recognise the Ford Pinto. The photo's they show are of a Ford Pinto with a modified front end. The original vehicle used a stock Pinto body and manual drivetrain with the 3 cylinder Kubota engine. The Kubota was an almost drop fit into the Pinto with very little modifications to mate it to a stock drivetrain. It got a real world 80 mpg but it took a little getting used to it's driving characteristics-very slow through the gears but once at speed it does OK. I have thought over the years of doing the project but you know how that goes .

 

My experience with the 302 tells me that 2800lbs. is the max we should ask it to pull.It is a high revving engine design and it must build those revs quickly inorder to be efficient.22-25mpg would be darn nice in a V8 F100! Maybe a 351W would be easier to get 25mpg+ .Look what NASCAR does with that engine.

 

I think I would try it on a 300 six, they seem to get the better mileage. Or even better use something like a 4 cylinder cummins diesel. Sounds like a cool idea, if money was no option I would look at a fiberglass body from us body.

 

Scrap the truck idea and get one of those kits.

 

Hell if that's the answer i got a motorcycle that gets 70mpg, but that's not really it. The cummins diesel is too heavy for an F-100.

 

The Cummins 4bt series engines are not too heavy for an F-100, but they are not a V-8 either. Would be a slick choice if mpg was the only consideration.

 

dump that edelbrock carb, rebuild a qjet and get it tuned the way you want it and slap it on there, youll love those smaller primaries, the increased torque and mileage

 

terran-
buy a honda

 

It requires modifacation the cross member.

You buy a honda, and i'll borrow it.

My milage went up after i switched to the Edelbrock.

 

Quote:

Originally Posted by classic79

<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /><o:p></o:p>

<o:p></o:p>

<o:p></o:p>

I am glad someone mentioned this. A buddy of mine has an '02 Firebird, which witch a double overdrive (factory 6 speed) only gets about 27 - 28 MPG Highway. I applaud you for trying, because we all feel the pinch with the way gas prices are going, but like the others I just question whether it is realistically possible. <o:p></o:p>

<o:p></o:p>

That being said my roommate in college had a 78 150 with a 390 2 bbl carb and 35's on it and if he kept his foot out of it he could get 19-20 mpg, so it is possible to get better then the 8-14 I get with my 79 150 with a 400 Holly Double Pumper 600, and 35's.<o:p></o:p>

<o:p></o:p>

I assume you have a 2WD since you talked about a body kit. But the keys you are going to want to look at are keep it as light and low as possible as the others have said, but one thing that hasn't been mentioned is compression ratio, I know power goes up as you increase CR, and I think efficiency goes up as well, I would have to do a little research on this. Personally I would still shoot for running Low Test gas due to the current price, but anything you can do to free up the enigne to pump the air through it would help too. Port and polish heads, intake and obviously run headers. I would also minimize any accessories, power steering and AC got to go, consider running an electric water pump and fan so your engine is only running an alternator. Running a cold air intake would help as well.<o:p></o:p>

<o:p></o:p>

For drive train, stay with a manual, and get as tall of gears as you can drive around town with, and get some form or a doubler or bolt in overdrive even if you are running a 5 speed, and try to keep your RPM at about 1500 or less at highway speed. You wont have much power at cruise, but you wont burn much fuel either.