i have a completely rebuilt 250 straight six in my 76 maverick. it has the auto transmission and single-barrel carb but i only get 13 mpg on a good week. do i need a whole new transmission? do a need my carb tuned or a new one of those too? what could the problem be?
I have the same combo in my 77 and I get about 19 hwy and 16-17 around town. Have you given it a good tuneup or do you know how long it has been since it has had one? There are a lot of things that effect gas milage including tire air pressure, condition of the air cleaner, condition of the engine, Carburator and even a blocked or restricted exhaust system. First you might want to make sure the choke is opening up properly and then check the plugs and see what their condition is. Make sure the air filter is clean also. Good luck.
Check the obvious like timing, choke etc. Check your tire pressures.(gets overlooked often) Also if its a fresh rebuild it could be tight still. They get better after break in.
I went from 17 mpg to 25 mpg by swapping to pre emission timing gears and re-curving the advance weights inside the distributor.
The driver has the most influence on the mileage of the vehicle. accelerate slowly - try never to use your brakes, keep your tires inflated properly, use the skinniest tires you can, let your transmission shift itself (automatic), optimize your temp and timing.
