The Stovebolt Site Forums The Shop Area General Truck Talk Mileage/fuel economy thread! (Post yours!)

As the title says! My personal results:

1965 C-10, 3.73 open rear, 31x10.50x15 drive tires (14.5" loaded radius), three speed SM318 and 230 with a slightly later Monojet. Engine is stock, complete with ultra high mileage and stuck lifter. (I figure at least 400,000 since the head's been off. Low drag rings courtesy of time?) Carburetor should have stock jets, idle mixture tuned lean. Timing bumped up to 8 degrees initial. Had an electric fan and fuel pump at that time, also. Mileage was about 18-20MPG @ 50-55MPH or so.

1966 C-10, 3.08 gov bomb, same drive tires as the '65, 3.11 first Saginaw 4 speed. 350 with Edelbrock #1406 AVS copy, Chinese dual plane intake, flat top pistons, stock profile CS274 cam. About 90,000 on it since it was rebuilt. Vortec heads. Flex fan, electric fuel pump, point and coil. Got 16-17MPG or so on it's first run with the 3.08 gears going about 60MPH. (Didn't get any numbers with the 3.73s)

This was done using google maps to calculate distance, then parking the truck in the same spot and adding fuel up to a dipstick level by weight. The same route more or less was used both times, mixed rural highway/town with some fairly good hills. About 90 miles total.

I'm going to make a 6 gallon strap-in tank to put in the bed next, so I can just weigh the tank to determine fuel used. Should be real accurate and also allow me to do some shorter test runs.

What's your mileage with your truck?

Results are in for today's run in the '66. 54 miles, a lot of that city, three gallons, so 18MPG. Not bad!

I don't know the MPG but my 49 stock 235 with changed out open drive with 3:90's is BAD. I think if I looked real good I could see the needle move. Maybe the gauge is wrong, I really don't know.

I stopped checking when it was 10 mpg, but it seems to get much better gas mileage now, with 3,000 miles, advanced timing and premium gason the 350.

64' C-10, rebuilt 230 w/ slight RV cam, stock 1 bbl. carb, 3 on the tree,3:73 gears and 15" tires, and I'm lucky to see 16-17mpg at Interstate speeds of 60-70 mph. Getting ready to install T-5 and that should help some. Let you know how it works out.
Tramp

....gulp, gallon.....gulp, gallon. At 90+ it takes more

I'm getting a solid 10 MPG on the 85 3/4 ton GMC....

The 52 is getting superb mileage! It runs as long as I keep putting fuel down the carb!

My '55 T.F.,is getting about 13-15 M.P.G.,depending on city,or hi-way. Rebuilt head,rebuilt carburetor,Fenton headers,and backed-off front brakes.(Still excellent pedal-new wheel-cylinders). P.O. told me he averaged 6 M.P.G.! Quite an improvement,and not bad fuel-consumption,for a 57-year-old 2-Ton! B.T.W.-261/SM 420/not sure hi-range 2-speed ratio?

about 10 mpg over about 10k miles and 12 years

The star of my fleet is our '50 4dr sedan, all stock 216 3 speed. We usually are in the 17-18 range on the highway. We just cruise along at 50.

1954/3100/235, dual carbs offy intake, fenton headers s/10 5speed, 2.73 nova rearend and 235/70/15 tires. 16.5 in town and high as 26.6 on highway but down hill in the mountains. 22-23 average too Kansas city. the amazing thing too me is i just bought a new GMC Terrain it weighs 4100 pounds empty and i am averaging 23.6 around town driving. i have not had it out of town on a real long drive.