Navionics fuel use meter, does it work?
 

Instead of a Garmin GPS system, I want to try the Navionics GPS system, but I want to know if the fuel use meter works well. I know with my Garmin system I can connect actual fuel flow sensors, but with the Navionics you input the cruise speed and GPH use at that speed. It seems like it would be a linear function but as we all know fuel usage is not linear. For the people who do use the Navionics, do you use the fuel usage?