I was just wondering what i can expect
Mine is bone stock and i just wanted to know whats the best you can get stock and a little beefed up(or major mods)
I'v had my truck for a while know, but my gas gauge dosent work so i wouldnt know how much im getting

 

You don't need a gas gauge to figure out mileage. Just fill up until your full and drive around and put some mileage on it--say 100 to 200,then fill it up. Div. the number of gals it take to fill up into the miles you drove. That will be your miles per gal.
The 400C wasn't much for mileage and with that large 2 barrel carb it's not easy to get good mileage. Headers with a dual exhaust and a 4 barrel intake with a 600 Holley set up with the Black vac sec spring and a 2 stage power-valve will get you the best. Also learn to drive using a Vac gauge for best mileage. I have a Edelbrock SP2P four barrel intake for a 400C for sale if you want to go that way.

 

It depends on your truck, too. My dad had a brand new 78 2WD F250 with the light gross weight that had a C-6 and fairly high gears. with 7.50-16 tires, it regularly got 15-16 and a high of 17 when Dad was driving it to work. Two years later, I could figure on it getting 15 with my 16 year old butt in the drivers seat.

My 77 1/2 4x4 with C-6, 4.10 gears and 315/70R16's got 8 with the stock two barrel, less when heavily loaded. When I put the Edelbrock performer intake and Edelbrock carb with stock metering rods on it, it went to 10-11 on the highway at ~3,000 RPMS.

Light foot+tall gears and tires= decent mileage. Low gears=high RPMs at todays highway speeds, which equals crappy mileage. I am not driving mine right now, due to fuel costs.

Robert

 

With the goodies you see in my sig, and with 3:50 gears I consistently get 10mpg. I keep it tuned up, change the oil regularly and hardly ever tow anything. When she was bone stock and the 31in tires....I got 13mpg on the interstate.(65mph)

 

How much do you guys expect me to get?
I have a 4 speed with the bulldog tranny
And 35 inch all terrain tires + 9 rear inch I believe 3.55 or 3.50 gear ratio

 

I have always believed that with a typical 3/4 ton 4x4 you should expect 10mpg, with a 1/2 ton 12 mpg; as a general rule. Then you can look at any better figures as a bonus.

Anything you do can effect the mileage, usually in a downward direction. Taller tires will give a slight overdrive effect, which may be offset by increased wind resistance. It really depends on where your engine has enough torque for the speed you are driving.

Be aware that the tires will throw off the odometer when figuring mileage. My truck (F250) with LT315/70R16's was off by 10 or 11 percent (checked with a GPS).

Drive like your mother is in the truck and you will get better mileage than if you drive like you are Mario Andretti.

Robert

 

Yeah, i need to find a good/ cheap GPS
only reason why i haven't bought 1 is b/c my lighter is getting no current to it

 

X2 1000%

Throttle opening is the by far the #1 factor of fuel economy

 

t18 4spd, 35/12.50's, 4.10 gears, full length headers, holley 670 on an edelbrock intake, DUI dist,E3 plugs and a bit of a lead foot and my average is 8.11mpg. before a complete tune up and the all new ignition system i was getting 6's and now im getting 10's so my average is going up tank by tank. I have an app on my iphone called car minder. every time i fill up I tell it current od reading and gal of fuel. it keeps a running total of mileage, charts it and keeps track and reminds me of when different services are due. easy to use and handy as can be. I keep all my vehicles in it.

 

Mine is a 1981 Bronco.....about 6-7" lift SAS, ZF5 manual trans 0,83 5Th gear , 35" tires and 4,10 gears and I get 9.4 to 10.2 MPG at 2800RPM...about 85MPH.......if I run it at 65MPH.....the MPG is almost the same...

The engine is brand new (3000 miles on it) has edelbrock performer intake and camshaft, edelbrock 1405 carb, Hei distributor , 9,3 TMeyer pistons and Heddman headers....

 

new to this forum or place, but been reading it for a while before i became a member today, i can tell u i get **** for mileage about 4 lmao, 35' tires 3.50 gears and modestly moded 351m.. wish i would get more but hell i love the mud and she is my toy for the races

 

Thinking about getting a new motor for my 1977 Ford F-150. Wondering what you guys think I should get

 

Naw, it's how heavy your foot is and how often you nail the go pedal. Everytime you nail that pedal, 3 cc's of fuel gets wasted (on a stock carb) Out on the highway, wind resistance is the major factor. Gearing only comes into play when the engine's out of it's sweet spot in the rpms.

 

The stock carb had little to do with it. The cam specs, pistons too far down the hole at TDC and smog equipment were the culprits. And converting to all that will do squat if he's got a lead foot. And the SP2P ? nothing but a throttle plate restrictor. Worst intake ever designed.

 

Since we're replying to a 7 year old thread, might as well join haha! I get usually 10-12mpg in my lincoln with c6, 2.75 rear end. Hoping that goes up a bit with the EFI conversion.