Throttle Control Dead Zones

A point I would like to review is that the amount of fuel used to cruise at any given airspeed is NOT proportional to RPM.

If, for example, your airframe requires 80 Hp to fly at 100 mph, it does not matter if that 80  hp is coming from a prop turning at 4500 rpm and 94 lb∙ft of torque, or 5400 rpm at 88 lb-ft, it is still 80 hp and will require about 6 gallons per hour to do it in either case.

Pitching UP the prop and slowing the motor does NOT save fuel.

At 4500 rpm, the engine may be turning 20% slower but with the higher manifold pressure, it will burn 20% more fuel on each stroke.  It is a wash!

What it does do that makes a difference is that it will run hotter and stress the drivetrain 20% more.

There is no advantage to running the engine at low RPMs.