The data is correct on most such as temp, gallons per hour, voltage, etc. What is wrong is mpg, fuel distance,etc.

It’s strange and galllons per hour is correct and speed is correct? You would think the mpg would be correct because it’s just the speed divided by galllons per hour.

After working with Humminbird the final on this is they will have to do a program update to get this correct. I flashed the newest program to the unit. The fuel mileage was closer at about 10 to 20 times the actual. I can put the fuel burn rate and gallons in tank right next to each other so that’s pretty good on knowing range.

Boat gets right at 4mpg at cruise of 40 mph.