Re: Fuel consumption vs. RPM
Yes, it does, but picture it this way...If you run a 25 pitch prop and at WOT (butterflies wide open) and engine is turning say 4000RPM, you have a high manifold pressure/low RPM situation.<br />OK, let's say now we are running a 19 pitch prop at 5800RPM...we have less manifold pressure/high RPM.<br />OK, now lets back down to 25MPH, the 25P prop is requiring the butterflies to stay at 3/4-full open to maintain that speed because it is way below the torque curve..the 19P, on the other hand, shows the butterflies to be at 1/3-1/2 open because we are in the middle (or close to) the torque range, but still at 25MPH. We have more RPM with the 19, but lower manifold pressure (some will say vacume) so we are doing less work requiring less fuel.