Fuel economy is normally expressed as “distance per volume” (mpg) or “volume per distance” (l/100km). Normalise that, it has units of area. I like to visualise that as the cross-section of a string of fuel dragging a car along, being thicker when accelerating and thinner when running down hill.
Acre-feet is a weird unit for volume, but if you know how big your reservoir is in acres then at least it’s an easy conversion to depth. And at least it’s just a conversion factor away from a sane unit that can be used for pump sizing and such.
Fuel economy is normally expressed as “distance per volume” (mpg) or “volume per distance” (l/100km). Normalise that, it has units of area. I like to visualise that as the cross-section of a string of fuel dragging a car along, being thicker when accelerating and thinner when running down hill.
Acre-feet is a weird unit for volume, but if you know how big your reservoir is in acres then at least it’s an easy conversion to depth. And at least it’s just a conversion factor away from a sane unit that can be used for pump sizing and such.
Another nice way to visualize the area of fuel economy is just the cross section of the fuel hose going to the engine.