In my searches here i've picked up a stray recommendation here and there, and no thread I found that addresses my question so I thought i'd start (another?) one so maybe someone else will pick info up easier (like me).


ok, recently I got a 65 with a 390 2 barrel carb in it, and I havent actually road checked the milage but if the owner can be believed, they said they got 11 MPG.
my engine is pretty stock as far as I can see, and the heads are 428's (a whole other length thread to find out what that deal was).
the question of the day IS; what can a guy do to get the most MPG's out of this engine? what can be added, taken of, replaced, adjusted tweaked or smacked with a hammer to make it get better gas milage?
All advice and ideas I greatly appreciate and read with great interest... sometimes twice or 3 times.

I know i'm not gonna get 20 MPG's but surely I can improve on the 11 MPG's!
I can do most of my own engine work, and what I cant I can get done for a case of beer.
if I can get 18mpg I'll be hopping happy!

 

A good hot ignition free flowing exhaust and a well tuned carb will get you better than 11MPG I would hope. I would also go with a new cam like the crane 901. I get 12MPG on the freeway with my setup. You can look at my gallery for the specs.

 

It's all about efficiency. Thermal coatings wear out. Fancy oil has to be changed. You need to follow the oem's trends. Roller lifters, roller rocker-arms, short skirt pistons, long rods, fuel injection, exhaust tuned for maximum efficiency at your cruising rpm. etc. etc.......

Short of all that junk, you need an electronic ignition, preferably MSD or Jacobs type. Synthetic oils in everything. A perfect tune on the carb. Max tire inflation you can run without wearing the tires out in the middle. Cruising rpm optimized for the lowest rpm with the best mpg return.

I had a 65 F-500 that had a 390 with a 4 spd trans and 2 spd axle. On most any given day it would give 10 loaded and 14 or so empty. It was bone stock with a dual exhaust. Points ignition, holley carb and keeping speed to 65 or less.

 

is there anything to be gained by adding headers and are they worth the time/money/effort for the mpg gain you get? if so why exactly do they work better than the stock manifolds?
ive got duals on now with little box mufflers I will be replacing with cherry bombs later on, I assume the streight thru pipe on the bombs are better than the baffles in those lil box mufflers.
the last owner said they put new cams and rollers in when they replaced the heads, but they didnt say what kind, so I am assuming they were just "stock".

 

Yes, the headers are worth the bother for helping fuel economy. The FE series truck engines have the worst flowing factory exhaust maniflods I've ever seen. If the engine is using less of its own power to push out the exhaust gases, there will be more power at the wheels, to push you down the road. Dual exhaust helps, as do the right mufflers. Don't discount the 'box' mufflers, some of them are very good. And cherry bombs, going straight through, may be louder than you really want. Some straight throuh glass packs have perforations on the inside of the tube that hurt flow. How big of exhaust pipes are you planning on ? What ignition do you have ? Driving style matters alot too. DF

 

I get 15 mpg out of my 360. Here's what I did:

Get a 4-barrel intake and carb. The smaller primaries are better for mileage. The only trick is to keep your foot out of it. When the secondaries open, mileage gets sucked right down them!

On the carb, run the smallest jets you can without making it ping. In my holley, I'm running 69's in the primaries, and 74's in the secondaries.

Advance the ignition to the point that it pings, in 2 degree increments. When you find the point that it pings, back it off 2 degrees. I have mine set at 12 degrees BTDC initial. To set timing, make sure you've pulled the vacuum advance tube and plugged it (a golf tee works good). Dont forget to plug it back in when you're done, as having it off will kill your mileage.

You can play around with different advance springs in the distributor too. Try to find the lightest one you can go with that doesnt make it ping.

Get a stronger coil. I got the accel super stock coil for $30. It allowed me to go .045" on the plug gap, and did seem to make it run smoother.

Make sure your cap, rotor, and points are in good condition.

Basically, do a lot of experimentation. One weekend should do it. Have fun!

 

Mouse, You can get all kind of answers here. First thing you need to do to ask these guys here is, tell them how much money you have to spend, and what you can do yourself. Answer these questions first.

How much money do you have to spend on your truck?

Will you be doing the work or hiring it done?

What rear gear ratio are you running?

What size tires are you running?

There are many things to do but none may apply to you.

John

 

DURALUBE.
Yes, it does work.

 

Duralube contains chlorine. Chlorine and oil mixed make a super lubricant but it will eat at your bearings and gaskets. Dura-lube is never going in any of my engines.

 

How much money do you have to spend on your truck?
whatever it takes within reason. about 250 Aa month is what i can spare.

Will you be doing the work or hiring it done?
I do my own work, and what I cant i can get help.

What rear gear ratio are you running?
havent a clue, standard f250 camper special rearend and transmission.

What size tires are you running?
chubby 16 inch tires, i will post the exact size tomorrow when I check them. they are brand new. they aint big mudders, just chubby 16's.

ive used duralube before i never saw any improvements.
i do use marvel mystery oil and that does show good results. in my nissan it runs better and boosted my mileage about 2 MPG on average, and on vacation on the highway i was getting 27 MPG, before on the highway I was getting 22-23 mpg. I dont know what it does but I add it to my gas all the time, when I dont the old nissan has all kinda odd ticks and clicks inthe engine, with it in the gas and oil its smooth and quiet.
whats the deal with mr marvels mystery oil anyhow? what is it? it looks like transmission fluid!
makes great oil for just about everything.. air tools, clock gears, keeps nuts from rusting on the bolts.... ect.

 

Stock Ford v-8 Trucks can do better than 11 mpg, at least without air conditioning. I've also noticed my truck and car's gas mileage does goes down noticeably when burning modern reformulated gasoline.

I'm suffering through 11 mpg with a freshly rebuilt 76 390.
The 4-barrel Holley carburetor needs sorting out, though the plugs look good when I pull them.

Back in the days of leaded gasoline, 1980, I went from 13 to 15.5 average when I had a C-6 rebuilt on a 1972 f-100 truck with 100,000 miles, stock 360 2-barrel. At 55 mph it would nudge 17 mpg on a cool, windless day.

I've personally witnessed big ford pickup trucks getting pretty decent mileage. In the early 90s, I had a freshly rebuilt-460 f-250 camper special with original c-6 transmission, 150,000 miles. It averaged 11-14 at 65 mph, depending on wind and hills. It would still average 10 mpg pulling a big cow trailer, if I used a light foot going up hills.

Also drove a 1961 f-600 flatbed with two-speed rear axle, with a fresh 292 Y-block back in the mid-1970s. It easily cleared 10 mpg empty.

 

I consistently get 15-16 mpg in my 1/2 ton 65. It is a stepside though and a bit lighter than most. Don't haul many loads. When I keep my foot out of it and run 60-65 mph, I do really well. Soon as I kick it over 2600 rpms though, mpg goes south pretty quick.

Running 390/ 4v with Holley 670 cfm Street avenger; C6 fresh rebuild; 3.25 rear diff; 255 70R15 BFG T/A tires. Duraspark ignition and a Flamethrower coil.

Good Luck!

 

I agree with scamardo on the RPM issue. All FE's I have had like to be in the 2300-2500RPM range anything higher and the mileage goes south of heaven that is for sure.

 

I agree about FEs and RPMs, 65f100coryE.
1st car was a 63 Ford Galaxie, 352 with three-speed overdrive. It ranged from 17 to 19 mpg at 60 with overdrive engaged, under 15 when in direct dirve. (Metal info tag said 4 to 1 axle ratio.)

 

This may seem really obvious, but may have been overlooked. Lower your tailgate or get a tonneau cover. I get about 2-3 mpg better if my tailgate is down.