It is not a carb
but if what you desire is better fuel economy
and also the ability to get best power
a TBI or MPSFI setup
could do up to 30% better.
If you are on a limited budget
factory EFI units pulled
from a junkyard
(Chrysler, GM or Ford units all could work)
would give acceptable results
I would also urge not neglecting
the easy Highway MPG gains
that can come from aerodynamics
or easier rolling resistance tires
It is hard to improve engine efficiency
but this article does show
that improvements have been made
with operating near the limit of lean air/fuel
including much research by Chrysler:
http://www.designnews.com/article/9710-Thirty_Year_Quest_for_Lean_Burn.phpit is doable
to get your Duster over 20 MPG
without breaking the bank
