In order to reduce overall fuel consumption on a twin boat I'm thinking about running a twin screw SD boat using one engine at low RPM for 4-6 hours and then at 75% for 1/2 hour before switching to the other engine?* I would assume that the loss in efficiency due to the rudder angle drag would be minor and I would be able run the one engine closer to it's 75% sweet spot.* I would also assume that an autopilot would be able to hold when running on that single engine.* Has anyone cruised this way and if so have you got any fuel consumption numbers (twin vs. single)?