I tried one of those china boxes, I could not even get it to show up on my garmin 8212. I am not the most techy guy though so it could be on me. I also have a alba combi that I kinda had working but support sucks since they are not in the states. I now have a pair of noland rs11s that I am working on getting installed, just looking through the instructions, they seem much more user friendly.

Yes, MEFI controllers (which the 502 Mags used) have an estimated fuel flow parameter. I have Fox-Marine gateways pulling data from the ECU’s up to my Axiom. Here’s my Axiom displaying fuel flow and inferred consumption data from my HP500EFI’s which run MEFI 3 controllers.

The Raymarine Lighthouse operating system has a Fuel Manager function that you set up the tank parameters in and then log fuel ups/top offs. It then uses the MEFI fuel flow data to estimate consumption information like MPG and DTE (distance to empty). So far for me, it’s been surprisingly accurate.

That's how ya set up the Axiom to get MPG then.. Teaching me something today.

Here I thought it was just because I'd never topped off the tank yet.

Glad I chimed in then!

I need to look into the fox marine gateways, and If my German could do the same thing. That would be really helpful since my boat only carries about 120 gallons.

can you send me the info ken on where to order i needs twin systems for holley terminator x