GeorgeC1 said:
Keep in mind that fuel flow is load not rpm dependent. If you are running both motors at a given rpm there will be less load and lower fuel flow then just one motor on a per engine basis. I experimented quite a bit with a voyage 440 cat on one verses two motors. In the end I found that if you ran two motors at the same cruising speed as one motor the difference in fuel burn was about 20%. The big savings comes from slowing down.
G
You're correct George. For me to regain the 0.8 kt speed difference running with just one engine, I have to raise it by ~300 RPM which lowers my net fuel savings from 100% to 25%~50% depending on the reference cruising speed/RPM (more savings at lower speed/RPM).
