MPG's

[R Pope]

You guys should live in Canada, we get over 20% better mileage up here! (Bigger gallons!) (End of joke, laugh here.)
An FE buddy sez "If gas prices weren't a factor, everybody would own 390's."
I agree with the post that said to go to a 4 barrel. The weight saving alone with an aluminum manifold has to be worth a mile or two! Don't get carried away with CFM, 650 or so is fine. And get rid of those horrible exhaust manifolds. FE's love headers.

[64 f100]

I drive my truck every day, at present it's my fishing truck. Mild cam 390 with overdrive. I am guessing at 10 mpg average, but think it could get better, if I could keep my right foot under control. I know that it's misses when cold as I can hear it popping back in the headers when I take off. Cheap gas that isn't cheap and not rated for high compression. I drive my truck like I stole it and don't feather it. If I wanted that kind of driving, then I would go and buy something modern like a prizm. The stock gear ratio was usually 3.89 with the granny four speed previous to 64. Trucks were built to pull a house off the foundation in low gear ( believe low gear reduction was like 70 to 1). Work trucks don't you know. As to what gear ratio would be best for one of these trucks, I would suggest 325 or 350. Any higher and you will have to use the granny low for takeoff, then have to shift imediately. You should be able to achieve 15mpg with a ratio change. Back when these trucks were new, I borrowed a freinds 65 longbed with with stick and overdrive. That truck got between 15 and 16 mpg. The overdrive usually came with 3.50 gears. I drive one equiped this way, and pulling heavy loads it is tough on the clutch during takoff. With the granny low you don't have to worry about takoff but you have to shift so soon you need to get it moving so you can make the shift to normal first. If you install a 275, let us know how that turns out.

Rich

[ICEMAN6166]

It's depressing when you think of it as $0.36 a mile.

i dont think that way at all.

i own the slicks outright they are inexpensive to insure and i can work on them myself.plus they are trucks and get used as trucks and have a full frame and thick sheet metal made in USA.

compared to new junk

big payment,high insurance, cant work on them. thin skinned, plastic coated with too much crap in the cab you dont need.

i vote slick, who cares about mileage, i win in every other category.

[charliemccraney]

I agree with Ice.
$2000-$3000 for one of ours or what, $30,000 for a new truck + interest + insurance + tag fees + 23 years of emissions testing + not much better fuel economy if it's better at all. Add all that together and see what the "savings" is. Of course, the longer you own it, the cheaper it is, but you'll have to own it quite a while to save anything. For the average person to buy a new car and really save money, it would need to be less than $30000 and get over a hundred miles to the gallon. Ain't gonna happen any time soon.

Old stuff is not bad. It's just sales propaganda for the new stuff. The only benefit to new stuff is that they may be cleaner. I say may because the emissions systems simply convert what they are looking for into something they aren't looking for. Is it necessarily cleaner? I don't know.

[frdnut]

We were getting about 15mpg with ours on the highway..It has a 390 with a 600CFM edelbrock carb and a set of headers..At that time it had 2.50:1 rear gears so it was like being in overdrive on the highway...The wife absolutely hated the gears driving in town with the three in the tree so I swapped in a set of 3:1 that I had laying around..Haven't rechecked the mileage since.

[MadMaxetc]

My 67 gets 20mpg Hwy and 15 city.

Figured when I drove it every day to work it cost me $1300 a year. That is repairs, gas, insurance, tags, etc...

That is about $0.40 a mile. to compare my new truck is $1.80 a mile.

[Anthony]

It's depressing when you think of it as $0.36 a mile.

i dont think that way at all.

i own the slicks outright they are inexpensive to insure and i can work on them myself.plus they are trucks and get used as trucks and have a full frame and thick sheet metal made in USA.

compared to new junk

big payment,high insurance, cant work on them. thin skinned, plastic coated with too much crap in the cab you dont need.

i vote slick, who cares about mileage, i win in every other category.

with Ice... even when mine is done I will only have about $8000 in her and have a lot of new parts and painted with cheaper insurance and no monthly payments... when you factor in all those things with a new truck then add your gas... you have to admit, ours are ultimately cheaper... drive'm 'cause you luv'em

[BarnieTrk]

I filled the tank two weeks ago and again yesterday. I got 9.8 mpg on the last tank.

What is your engine timing set at? 6*
What brand of gasoline are you running in it? BP mostly
What is the gasoline's octane rating? 87
What % of your driving is over 60 mph? 10%
What % of your driving is under 50 mph? 90%

For your 352-V8-powered, NP435 4-speeded, DANA 4.10 geared, 4,000+ lb (empty) F250 to get an average 10 mpg, I'd say you're doing PRETTY WELL!

BarnieTrk

See bolded answers above

As I recall, your '65 352 would have about a 9:1 compression ratio new/fresh.
I bet you'd get better mileage if you bumped up the timing to 10* and used 89 octane (mid-grade) fuel.

BigMike,
I challenge you to try these two changes for a similar two weeks as your first mileage test. Let us know how it does....

BarnieTrk

[Elliott]

I've only gone through three tanks of gas so far, second one i got 6.5, third tank i got 8. 352 with 4-speed and DANA 4.10 geared. It has a 600cfm Edelbrock 4bbl and headers. I wish it got better, for sure.

Mid range fuel made a little bump in MPG and made it run MUCH smoother.

[64 f100]

If any of you have ever checked your engines distance from top of cylinder to piston height at tdc, you will find the 352 is 100 thousandths down the hole, and the 390 is about 30 down the hole. There is alot of doubt in my mind about a 352 having 9 to 1 compression ratio stock inour trucks. I've never done the math but a 390 in a mustang GT was only about 10 to 1 . the difference in piston height is actualy a hair over 1/16 of an inch, but Ford was always rumored as overating the compression on thier engines in those days. The 390 2 barrelmodels were supposed to have a ratio of about 9 to 1. To achieve 10 to 1 you can use the 360 pistons. Readily available and not so pricey, you might also be able to use these in the 352 for an overbore of 50 thousandths, which would be a stock 360 piston. Anyway, it doesn't seem that with the extra 60 thousandths down the hole you would get the same compression ratio as a 2 barrel 390 engine. The difference between a 4 barrel and two barrel engine is a cup in the piston that drops the compression ratio. The 1/16 inch difference is a lot of CC's and the longer stroke should also mean higher compression ratio in my opinion. Again I have not done the math, but 8 to 1 sounds more in line with my thinking on a bone stock 352 with truck heads. You can achieve better ratio with smaller combustion chambers but those heads are scarce. I actually have a set of those heads. I value those at about 5 to 8 hundred, and no, these are not for sale.

Rich

[Toyz]

Posts seem to be disappearing!
There are a lot of external items which affect fuel economy. Checking the advance characteristics are always a good part of improving what you got.
Paul

[STOFFER]

my friend told me a while back

try to think of it as "smiles per gallon"

[jamesdfo]

It might be less painful thinking about smiles per mile, rather than miles per gallon:)

James

I'd like better mileage but it isn't a DD. I'd probably drive it more if it got 14-15 though. It's depressing when you think of it as $0.36 a mile.

[66fordtrucknut]

I get 17 hwy, 15 around town with a bone stock 223, single bl holley. Doesn't take you broke and still have fun with it, just I can't do a burnout.
Charlie

[BarnieTrk]

I've only gone through three tanks of gas so far, second one i got 6.5, third tank i got 8. 352 with 4-speed and DANA 4.10 geared. It has a 600cfm Edelbrock 4bbl and headers. I wish it got better, for sure.

Mid range fuel made a little bump in MPG and made it run MUCH smoother.

Elliot,
If you don't mind running another experiment with your truck, bump up your timing from 6* to 10* and then go with another one or two tankfuls of mid-range octane fuel. Track the mileage and come back here and report your results. I'm guessing you'll be pleasantly surprised.....

BarnieTrk

[ICEMAN6166]

I've only gone through three tanks of gas so far, second one i got 6.5, third tank i got 8. 352 with 4-speed and DANA 4.10 geared. It has a 600cfm Edelbrock 4bbl and headers. I wish it got better, for sure.

Mid range fuel made a little bump in MPG and made it run MUCH smoother.

Elliot,
If you don't mind running another experiment with your truck, bump up your timing from 6* to 10* and then go with another one or two tankfuls of mid-range octane fuel. Track the mileage and come back here and report your results. I'm guessing you'll be pleasantly surprised.....

BarnieTrk

FEs seem not to like lower octane. my wrecker runs far better and better mileage with 91.
the cheap stuff does fine in the 300 6 and the y block.

[douglloyd]

I'm running a 302 ahead of a T-18 4 speed with a stock rear end (never checked gear ratio) in my '66 longbed. It used to have a 352, but rather than rebuild it I pulled it and swapped.

Mileage isn't too bad, but as was mentioned earlier, the 302 is gutless. Mine has the Motorcraft 2100 two barrel and stock exhaust, so that doesn't help the "torque-challenged" problem when I try to tow.

On the other hand, I've recently run some long trips from east TN out to central Kansas and Arkansas this spring - was able to maintain 55 MPH on the freeway with the trailer, slower on the hills.

Higher octane gas helps a little bit as well. When I run premium through it we can manage to get over the Cumberland Plateau without getting in the way.

The only casualty was my credit card. About 3/4 through the third and last trip the company put a block on it. They couldn't believe someone would really go through all that gas

Doug

[brian gilbert soares]

"It's not about the MPG, it's about the smiles per mile."
and when you consider insurance savings, doing your own maintenance,
reasonable cost for some parts and riding in style.
Win, Win, Win, Win!
I've never figured out the MPG.
many miles, many smiles.

[bobenhotep]

I drove the rhino quite a bit in georgia, and got between 15 and 19 mpg, depending on how much highway was involved. Here in New Mexico, I have not driven much, so I have no idea. I can definitely feel a drop in power after gaining 4000 feet in elevation.

My setup.

300 6 cyl from a 1980 f100
-no ps or ac
-no mech fan
-synth oil

3 spd manual with synth oil

2.70 rear with synth oil

215/75 r 15 tires

may end up with a 4 spd with all the hills around here...

[64 f100]

Foodstick, I have ran into a 300 problem that may be realted to your mileage. The heat riser flap will break loose on it's shaft on some 300 sixes and baouncing around will cause more fuel consumption and a mild ticking noise. Also, I had an 81 van with a 300 and it had bad piston slap. Seems Ford did some kind of change for a couple of years to the engine. Looser piston bores somehow. I drove the truck untill there was smoke coming out from under the hood when I pulled up to a stop sign. I then installed a hot little 302.

Rich