I purchased the black box for connecting my 858c to an nmea network backbone. It all installed correctly and then I found out that the only fuel consumption readout available is gallons per hour. So in order to find out statute miles per gallon I have to take gallons per hour..OFF OF A COMPLETELY SEPARATE PAGE..and divide my speed in miles per hour by this number. When is humminbird going to take the information that the unit already has and provide us with a more useful number such as miles per gallon???
Also, with the information that this unit has I should be able to program in a tank size and have it calculate fuel left in the tank based on fuel consumption rate???