Piston aircraft engines with variable pitch props are almost always run full throttle unless the pilot doesn't understand altitude may be your friend or is just potting around with no mission or destination in mind. Unobstructed intake is always more efficient than one partially blocked off by a throttle plate....
Not really applicable to terrestrial engines unless stationary or operating in a constant loading condition sufficient to keep the engine below max RPM with wide open throttle.
Not really applicable to terrestrial engines unless stationary or operating in a constant loading condition sufficient to keep the engine below max RPM with wide open throttle.