What analysis?
Yes, most do affect mileage, but that is the particular mileage for a particular condition. Once you have that locked in, then mpg is a function of throttle position.
Whatever the Scion did, the mpg displayed and fuel consumption at fill up were consistent.
I'm trying to visualize a "carburetor" as a fixed orifice (fixed throttle position) where fuel is entrained as a function of Velocity (really V**2 but carbs are tricked out with secondary air bleeds and emulsion tubes to make them linearish).
Orifice discharge coefficients are not linear. At low flow they are failrly linearly however. So if you double the speed of the engine, you double the flow and V and double the fuel (assuming incompressible flow like a liquid). But you've also doubled the distance traveled too  per unit time(!)
Double fuel, double distance = same mpg.
So if the discharge coefficient is fairly linear, I guess it makes sense.
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If someone sees a different explanation, please expound upon it.
Thanks
Tom
