Gas Milage

[mopartruckguy]

I currently have a 1bbl carb on my 74 Duster and bought a 79 2bbl setup.
What one will get better gas milage?

[valiant64]

Thats really gonna depend on your driving habits, and how well the carb is tuned. I'd expect they'll be similar, but the 2bbl will make some more power for passing and higher speed operation.

[mopartruckguy]

I don't have a heavy foot, unless im showing off. That isn't very often.

[Skwerly]

Classically, it's the same as the "2bbl car vs. 4bbl carb" thing. Under very light pedal, the 4bbl carb will get better gas mileage because the primary jets are smaller than in the 2bbl, which have to accomodate for the entire RPM range. So, my guess is that if you keep your foot out of it, the 2bbl may actually outperform the 1bbl as far as mileage!

[big-Sarge]

I have a manifold that holds 2(two) holley 1920's and after good tuning and care Left foot adjust ment drives much nicer than 1(ONE) 1920 that was originally installed. I don't drive it often enough to get milage figures as the fuel evaporates too quickly between anual drives.

[N.R.F.D.]

the 1 barral will get better milage the four barral can get better mailage because the primary side is ussauly smaller then the two barral and carbs work on air speed the faster the air the better the mix the two barral might get better milage if it was a progressive primary secondary like a weber or like. of corse if the one barral is not tuned right it wont get better milage then a well tune two barra.l the difference is not much though i made the swap on a 70 challenger that i had and lost maybe a half a mile per gallon and picked up a bunch of power. it was worth it

[big-Sarge]

If I could find somone to retune my 32/36 weber maybe I would get decent mileage but it bogs on accelleration. It was from a Ford Capri V6 originally when new. I just thought that the dual 1920's might be more fun.
I also own a few sets of Dellorto DHLA carbs with a weber side-draft manifold, but this would require the propper cam grind like that in a BMW.

Sarge

[nhdriver]

Originally Posted by N.R.F.D.

the 1 barral will get better milage the four barral can get better mailage because the primary side is ussauly smaller then the two barral and carbs work on air speed the faster the air the better the mix the two barral might get better milage if it was a progressive primary secondary like a weber or like. of corse if the one barral is not tuned right it wont get better milage then a well tune two barra.l the difference is not much though i made the swap on a 70 challenger that i had and lost maybe a half a mile per gallon and picked up a bunch of power. it was worth it

I get my best mailage with a 1st class stamp from the post office. But unfortunatly it costs me about $.75 to get there due to the poor mileage I get w/ my truck.