Can anybody explain the dual FUEL CONSUMPTION curves provided by DD for each engine model? (These are the graphs showing HP and Fuel Consumption for each engine model. The dual HP curves on plotted on the top of each engine chart page, the dual Fuel Consumption curves are on the lower part of the same page.) There is an upper curve labeled FUEL CONSUMPTION, another lower curve which intersects at the rated engine RPM ,labeled FUEL-PROPELLER LOAD. The lower curve (Fuel Prop load) seems to be the consumption I experience, but what's the upper curve??? Thanks, Rob Brueckner Hello Rob I don't know exactly what graph your looking at but it sounds like the upper curve is showing fuel consumption at "RATED LOAD" which would be fuel used at any given RPM fully loaded for that RPM. The lower curve should be fuel used at a given RPM with a typical propeller load for that RPM. Both curves should come together at the maximum RPM because that would be the only RPM were the engine is fully loaded. Those curves are showing you the difference between the way the engine produces power and the way the propeller absorbs it. If you are proped to allow the engine to reach top rated RPM then only at top RPM is the engine fully loaded. At any RPM below Max your engine is actually under loaded. This is why the idea of under proping to combat weather or head seas has no merit unless your planing to run WOT in those conditions. Brian Palmetto FL