Poor mileage
Thread Starter
|
Freshman User
Joined: Feb 2003
Posts: 40
Likes: 0
Poor mileage
Hi, I have a 1970 F100 Sport Custom, 302, 3 speed manual, 3:55 rearend (i think) I am having a real issue with the mpg's. When I first bought the truck it was getting around 8 to 9 miles per gallon. Since then I have done a vast array or tune ups to get her running better and I have managed to get it up to 13 mpg. I had a 2bbl carb rebuilt for it, it came off a 1979 LTD. If anyone can give me suggestions on how to improve my mileage I would appreciate it as i would like to get her up to 18 mpg or better.
PS, what is everyone else getting for mileage?
PS, what is everyone else getting for mileage?
Senior User
Joined: Aug 2002
Posts: 327
Likes: 1
From: Saskatchewan
Poor mileage
I have almost the same truck as you and that is what I am getting, and darn happy to get it. There aint a whole lot you can do, I think a 4bl helps alittle and better exhaust, go the more complicated way and put in better gears, but 3.55 aint that bad. I think that 18 is a pretty big stretch but what do I know I have been wrong almost once before (I thought I was wrong, but was actually right).
Freshman User
Joined: Jan 2003
Posts: 36
Likes: 0
From: Long Beach
Poor mileage
I have a '72 360 2bbl with a C6 and 3.00 rear axle. At 134,000 miles the engine has never been apart, and uses no fluids, doesn't smoke or leak a drop. It's the darndest thing I ever saw. When I first got it I would easily get 17 mpg on regular at 60-65mph on the freeway, but since I added power brakes, power steering and AC it has dropped to about 14.5 or so highway. If I try to push it much over 70mph it begins to eat the gas. The old guy I bought it from kept a log book of every little thing he bought or did to it and jotted down the milage. He was the original owner and treated it like a baby, only selling it because he turned 87 and was going deaf and blind. I have stock tires on my truck if that matters any.
New User
Joined: Jan 2008
Posts: 0
Likes: 24
Poor mileage
Hey Scott,
Here is one of my old replies in another forum.
I thought you might like this info.
*********************************
Things that improve fuel economy:
The general condition of the engine itself (rings/valves,etc)
Engine in proper tune with all parts operating correctly.
Clean air filter
Clean rotor and contacts in dist.
proper inflation in tires
less stop and go driving
proper gasoline per application
fresh gasoline(usually acquired at a very busy gas outlet)
Higher gear ratio (2.75- 3.00:1)
Keeping your foot out of the accelerator(EGG under gas pedal works)
Having the Proper thermostat in engine.
Weight that is being hauled.
Not having "Wind Drag"
SHORT warm-ups (not letting the just engine idle away)especially with the choke on.
Here is one of my old replies in another forum.
I thought you might like this info.
*********************************
Things that improve fuel economy:
The general condition of the engine itself (rings/valves,etc)
Engine in proper tune with all parts operating correctly.
Clean air filter
Clean rotor and contacts in dist.
proper inflation in tires
less stop and go driving
proper gasoline per application
fresh gasoline(usually acquired at a very busy gas outlet)
Higher gear ratio (2.75- 3.00:1)
Keeping your foot out of the accelerator(EGG under gas pedal works)
Having the Proper thermostat in engine.
Weight that is being hauled.
Not having "Wind Drag"
SHORT warm-ups (not letting the just engine idle away)especially with the choke on.
Senior User
Joined: Jan 2003
Posts: 451
Likes: 0
From: Balfour
Poor mileage
Your above average mpg's for these old trucks. I get 8-12 or so with my 250 w/390 and a small 480cfm 4v, my beater 4x4 gets 7 or 8 tops even going down hill!!!
I got 20+mpg once...... going down the other side of a mountain pass!!!
I got 20+mpg once...... going down the other side of a mountain pass!!!
Senior User
Joined: Feb 2001
Posts: 210
Likes: 0
Poor mileage
I have a 72 F250with a 390 auto and A/C. The parts stores used to have 160 and 180 degree thermostats listed for the application. I always picked the 180. I now see a 192 degree thermostat listed in Dennis Carpentor. Is anyone using a 192 degree thermostat? Have you noticed any difference or any benefits?Joe
New User
Joined: Jan 2008
Posts: 0
Likes: 24
Trending Topics
Elder User
Joined: Feb 2002
Posts: 542
Likes: 0
From: Middleton, WI
Poor mileage
Welcome to FE Ville, they do not like to pass too many Gas Stations, at least that's the general consensus. They' were created and used at a time when gas sold for 25 cents a gallon and if you think ours are bad you should talk to some 440 Mopar guys.
I've been driving mine with various engine configurations for 14 years (Incl. one cross country trip from CA to WI) and even with stock 352 (2bbl) I barely beat 12-13. With built 390 and an AOD tranny and 3.55 rear, I can get 10-11 on the Hiway. Surprised no one mentioned bed covers - they help, not sure how much, but it's gotta help some.
If MPG is your thing, I'd look for an I-6, or a 302.
I've been driving mine with various engine configurations for 14 years (Incl. one cross country trip from CA to WI) and even with stock 352 (2bbl) I barely beat 12-13. With built 390 and an AOD tranny and 3.55 rear, I can get 10-11 on the Hiway. Surprised no one mentioned bed covers - they help, not sure how much, but it's gotta help some.
If MPG is your thing, I'd look for an I-6, or a 302.
Last edited by CACWBY; Jun 9, 2003 at 05:47 PM.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
Top 10 Fords at 2026 Carlisle Ford Nationals
Joe Kucinski
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Thread Starter
|
Freshman User
Joined: Feb 2003
Posts: 40
Likes: 0
Poor mileage
I just installed a tach on my truck and it runs about 2500 to 2700 RPM at 60MPH. I think thats pretty normal isnt it? What should it be idling at? (1970 302)
I recently purchased a set of holley headers and i will be running 2 1/4 inch dual exhaust how much could this help mileage and horsepower?
I recently purchased a set of holley headers and i will be running 2 1/4 inch dual exhaust how much could this help mileage and horsepower?
Posting Guru
Joined: May 2003
Posts: 1,393
Likes: 0
From: Thomson, GA
Poor mileage
Idle for my 72 F100 302 is 800 RPM, not sure about an auto, but i think that it is 500 RPM in drive. It should be on the orange sticker on the drivers side valve cover, along with other specs like timing and spark plug gap. I also hear from the general conversation forum that leaving your tailgate up is better than leaving it down as far as drag and MPG... not much better, but better.
Senior User
Joined: Jan 2003
Posts: 451
Likes: 0
From: Balfour
Poor mileage
How much would it help MPG having those extras? More flow usually ment more gas could get in and out whenever I beefed the exhuast on my trucks. Thats just my experience though, some people claim good results with mpg improvement using hedders.
Freshman User
Joined: Aug 2002
Posts: 43
Likes: 0
From: SoCal
Poor mileage
Originally posted by muchtomydelight
I also hear from the general conversation forum that leaving your tailgate up is better than leaving it down as far as drag and MPG... not much better, but better.
I also hear from the general conversation forum that leaving your tailgate up is better than leaving it down as far as drag and MPG... not much better, but better.
Mountain Pass
Joined: Apr 2002
Posts: 230
Likes: 0
Poor mileage
I can get 27 mpg...
That is when I leave the truck home and take my car because I'm not towing or hauling something that won't fit in my car.
Otherwise I get 8 or 9 mpg with my 72 F-100 with a 390, PS, PB, automatic. I'm honestly not sure if it's a C6 or what my rear end is.
That is when I leave the truck home and take my car because I'm not towing or hauling something that won't fit in my car.
Otherwise I get 8 or 9 mpg with my 72 F-100 with a 390, PS, PB, automatic. I'm honestly not sure if it's a C6 or what my rear end is.