|
Carburetors add fuel based on the volume of air that rushes through them, but they don't on their own compensate for air density.
Warm air improves mpg because it promotes fuel atomization and allows for wider throttle openings per desired power.
Carburetors also do not compensate for air restriction. This is where air filter manufacturers pull their claims of improved fuel efficiency. A clogged air filter will cause a carbed car to run pig stinking rich.
An ECU in closed loop mode will maintain a 14.7:1 ratio regardless of how clogged the air filter is (short of total blockage). Whether your throttle plate or a dirty filter is providing manifold vacuum, your engine does not care, and is burning at 14.7:1 regardless.
|