It seems from different threads that some garmins are no longer calculating mpg. Did this feature disappear with a particular software upgrade? Mine is still working, but I also am A few versions behind.
Reluctant to upgrade if this will disappear as it my primary data point.
It stopped working for me in the Garmin upgrade published in April 2021 with the Yamaha to N2k gateway installed. Others were affected by this as well.
However... I just installed Autoglide on a 2025 R27 LE and had to add a Yamaha N2k gateway. His mpg is calculating correctly on the Garminw with updated software.
Yamaha has released 3 versions of the Yamaha N2k gateway. I have the original version from 2020. I suppose it's possible that Garmin updated their code, which broke it. And Yamaha has since fixed it In their newer N2k gateways.
If your boat doesn't have a Yamaha n2k gateway ('23 and newer models don't come with one), then you're using a J1939 cable from the engine to your chartplotter. It won't matter. You'll get mpg on the chartplotter no matter what software you run.
I do IT for a living. I upgrade all the firmware on my boat, regularly. The only rule against a firmware upgrade is that I won't do an upgrade unless I'm at my home port. If I'm out on a. trip, or at a guest marina, I won't perform upgrades. Chartplotter, Victron BMV, Solar controller, CerboGX, Peplink Internet router, Starlink... I keep it all updated on the latest firmware.
I also recommend upgrading the charts on the plotter as well. Especially if the boat's a few years old. The newer charts will clearly show the whale zones off South Pender island (by Poets Cove), to make sure you know where not to be. (It's a hefty fine if the Canadian coast guard catches you in there after June 1).
