J/30 Class Association Forums J/30 Forum The Boat, Sails and Equipment Engine Specs - speed and fuel

I have a 1980 J/30 (hull 201) with a 3/4-in. shaft, 2QM15 diesel, and a 14-gal fuel tank.
Today I found my 2QM15 Service Manual. It says the engine has a continuous duty rating of 14 horsepower at 3000 rpm. The most fuel efficient speed for diesels is supposed to be 80% of the max horsepower rpm and sure enough, the manual shows that the best fuel consumption is 200 g/Hph between 2250 and 2450 rpm. I'm guessing the units are grams of fuel per horsepower hour. At 2400 rpm the engine produces 11 horsepower.