My truck is a 1971 F100 with 302 automatic. I inherited it from my grandfather which bought it new. It has 72,000 miles. After several tankfuls the past three months of mostly highway driving I am getting only 11 MILES PER GALLON! Is this normal? How can I improve that?

My 1986 Z28 with a 305 automatic with 234,000 miles gets well over twice that same drive/conditions.

Thanks!

 

that's around the norm for mileage for these
trucks. My 70 250 gets 8mpg tops cruising like a
granny at 40mph,my 72 gets 16mpg due to higher compression,
and it's got a 390 w/holley 4v. Get dual gas tanks
it'll make you feel like your getting more mpg, and
ya won't have to fill up as much. Kinda like fixing
lifter noise by chopping the mufflers, gives ya
some peace of mind

 

I have a '72 302 with C4 and 3.25:1 rear end ratio and get about 13 mpg around town. I have headers, turbo muffler and a Pertronix ignition plus I converted to manual choke. All these things improved my gas milage so that's about as good as it gets, I think.

 

I get 13 mpg in my 71 f100 302/C4 combo. When I first got it it was around 11 mpg but it had been driven 500 miles in the last 2 years and needed a tune up. I remember when I was little my dad bragging to his buddies about getting 14 mpg once with his F250 2 wheel drive. These things just aren't real fuel efficient. My Dodge diesel gets 22 mpg on the freeway and it's 4 wheel drive, quad cab long bed. But my F100 is cooler so I drive it...

Pat

 

67 F-100, 4spd, 352, Petronix ignition, headers, in tune

10.6 mpg. I feel good having broken into two figures!
jor

 

When I got mine it got around 7mpg. After a carb rebuild and good tune-up it got a litle over 10 (maybe 12 on a really good day). Now that I've fixed the handling I drive it faster and the mileage is back down to 9. There isn't too much statistical bounce in these data. There are for several fill-ups on very similar routes.

You get very frequent fill-up data with trucks like these!


This is with a stock 360 2v, C6, and a 3.73 rear axle ratio.

--Matt


1972 F250 Custom Sport Camper Special 4x2 360 2v C6 3.73
Soon to have a 104" wheelbase as part of a Broncification project
My FTE Website -- http://www.clubfte.com/users/mlf72f250/index.html
My Galleries -- https://www.ford-trucks.com/user_gallery/displaygallery.php?userid=1108

 

My '71 F250 Camper Special gets 200 miles out of an 18 gallon fill-up. That comes out to about 11 MPG. I am very happy with that, since I only drive it about 100 miles a week. The previous owner replaced the exhaust with undersized single exhaust, which I feel is very limiting. I think it will get better gas mileage after installing dual exhaust.

John

 

Joey1986Z ---

Boy, maybe I should be thankful I get 11 mpg with my 460+ highway hauler ?!?!?....

 

I have heard people compare the older Broncos and trucks as to driving a piece of plywood (4x8) down the highway. Aero.... what? With any luck I should have my truck into the 8-9 mpg range soon!

 

before i took it off the road, my 68 shortbed with a '76 300/3speed/3.70 rear/31" tires got 11mpg . . . waiting to see what it will do with a mild 302 and C4.

my '49 F1 has a roller cam 5.0, edelbrock 600, T-5 5speed, 3.70 rear and 28" tires . . . it gets 15mpg if I'm squirreling around town, and 19+mpg on a long cruise.

I had a stock '49 with a flathead and 4.27 rear -- it got 6-7mpg.

Its funny -- the fastest/quickest/most powerful one also gets the best gas mileage.

Chris Seay
Bealeton, VA

 

It really is about aerodynamics. It seems that most old trucks get around 9-15. It really seems pathetic when my car will put over 300HP to the wheels, run a 13 Sec. quarter and get 30MPG on the highway.

 

[updated:LAST EDITED ON 18-Oct-02 AT 10:44 AM (EST)]>My truck is a 1971 F100 with 302 automatic. I inherited it
>from my grandfather which bought it new. It has 72,000
>miles. After several tankfuls the past three months of
>mostly highway driving I am getting only 11 MILES PER
>GALLON! Is this normal? How can I improve that?

I think it's worthwhile to see what a certain mpg will cost. Here's a table with mpg, a US average $ per gallon, and miles per year, and $ per year of fuel expense. The last column is the savings one would see from a 1 mpg improvement. As you can see, it would take several years time to pay off an overdrive if you're already getting fairly decent mileage. But if you're down around 9, it starts looking better. Of course it depends on how many miles per year you drive and the cost of the overdrive unit.

For me, since I get around 9mpg, that means I can feel good about spending $600 to get myself a 1 mpg improvement since I'll break even after three years of driving. Of course, I'd expect probably a 2-3 mpg improvement with overdrive, so that means... Hey! In my case, the economics tell me to maybe go ahead. So maybe a 5spd w/od or maybe an AOD with the special FE bellhousing adapter. Hmmm...

--Matt

[font color="blue" size="2" face="courier"]

mpg $/gal miles/yr $/year savings for +1mpg
7 1.5 12000 $2,571.43 $321.43
8 1.5 12000 $2,250.00 $250.00
9 1.5 12000 $2,000.00 $200.00
10 1.5 12000 $1,800.00 $163.64
11 1.5 12000 $1,636.36 $136.36
12 1.5 12000 $1,500.00 $115.38
13 1.5 12000 $1,384.62 $98.90
14 1.5 12000 $1,285.71 $85.71
15 1.5 12000 $1,200.00 $75.00
16 1.5 12000 $1,125.00 $66.18
17 1.5 12000 $1,058.82 $58.82
18 1.5 12000 $1,000.00 $52.63
19 1.5 12000 $947.37 $47.37
20 1.5 12000 $900.00

[/font]


1972 F250 Custom Sport Camper Special 4x2 360 2v C6 3.73
Some day hope to shorten to a 104" wheelbase as part of a Broncification project
My FTE Website -- http://www.clubfte.com/users/mlf72f250/index.html
My Galleries -- https://www.ford-trucks.com/user_gallery/displaygallery.php?userid=1108

 

fuel injection and overdrive transmissions are wonderful things . . . when everything is hooked up correctly and every little sensor is functioning correctly that is!

Chris Seay
Bealeton, VA

 

>fuel injection and overdrive transmissions are wonderful
>things . . . when everything is hooked up correctly and
>every little sensor is functioning correctly that is!
>
>Chris Seay
>Bealeton, VA

Tha Z28 I mentioned that gets 25-26 mpg does have overdrive, but still carbed, albeit a computer controlled carb.

 

thats about right i have a 70 F100 that got 8 mpg in town