Gas gauge accuracy

[Benz819]

I have an 819 when I filled the tank up with gas
which should have been 43 gallons I set the mobile vessel view
to 43 gallons. My vessel view now shows I'm down to 14 gallons left in the
tank but the gas gauge is saying I have 5/8 of a tank.Anyone run in to this
scenario before, just wondering if my gauge is off that much or is the vessel view
that accurate. I have noticed that when I turn the key off
the gauge only goes down to an 1/8 of a tank.

[Fidgetcranker]

Sometimes my gauge worked accurately, sometimes not, so I got the fuel manager hooked up thru NMEA for a digital reading.
The only way to know is for you to fill up and see if it takes 29 gal.

[greeneb]

Mine really likes to sit at that 1/2 tank area for a while. I agree with Fidge, best way to know what you got is to fill it up again and figure it out.

[Riccochet]

It's not just Phoenix. Those gauges are the most inaccurate pieces of poop made. Or, rather, the sending units. Mine bounces around all over the place. I just keep it full and don't look at the gauge.

[Mbeason]

So Tim explained this to me once. The Coast Guard does not let the fuel gauge say zero when there is no gas left in the tank. The way the tanks are made and sit under the seats, when the float bottoms out, or says ZERO on the gauge, there is still about 10 gallons left in the tank. But only one way to find out

[Phoenix Jim]

So Tim explained this to me once. The Coast Guard does not let the fuel gauge say zero when there is no gas left in the tank. The way the tanks are made and sit under the seats, when the float bottoms out, or says ZERO on the gauge, there is still about 10 gallons left in the tank. But only one way to find out

When friend’s 721 is on empty he has 10 gallons left. Wonder how accurate my 2018 920 is with smart craft gauge is

[fishin couillon]

Another thing to consider is how accurate are they saying that the size of tank is.....on my old skeeter i had the plastic retangle tank which listed it as 36.....after taking the measurements and doing the mathamatical route, the numbers show it to be 30 gallons.....so between actual size and sending units, tlhings wont be as accurate as you think (IMO).....on my skeeter, when guage showed me at 1/4 tank, it was 1/2 full.....on the Phoenix, i just fill it up at each outing and keep track on the Merc. Monitor as to how much fuel (gallons) it used for the day....

[Phoenix Mark]

Hard to beat a Mercury Smart Gauge. My fuel consumption is accurate to a gnat's ass. It also is helpful when you have a buddy riding along who is willing to share fuel costs.

[DREWTICK]

Besides the inaccuracy of the gauge itself you have to look at the shape of the tank,, same as the merc gauge, I use the Yamaha ECU connected to my Lowrance units and on every fill up its always less than 1/2 gallon from what the pump says.

[Tom Edwards]

I JUST put in my Yamaha Cable in the gunnel, among other wires and cables. Some day I won't be pissed and MIGHT get it into the console. :-)

[Tom Edwards]

Well, got all the wires and cables run, and tied up so they are neat. Now to make a bracket/plate for the little switch, maybe get it powder coated, and install the hydro plate. That'll get done after my knee gets better, inflamed now for some reason, and has been for a month, am limping around.

[Fidgetcranker]

The Fuel Manager that hooks in thru NMEA works great on my sho. Set it to full when I filled last week...
It said I used 33.1 Gal. Got gas and it took 33 gal!
Directions says, if you used so much, but the amount of gas you put in is different, there's a way to calibrate the monitor to work accurately.
Mine works fine right out of box tho, and most will, but some need to be calibrated.

[Tom Edwards]

Where do you get one of those Fuel Manager things, and how is it wired in?

[txbass1]

Where do you get one of those Fuel Manager things, and how is it wired in?

https://www.lowrance.com/lowrance/ty...8aAouYEALw_wcB

And you just hook it into your network

[DREWTICK]

mine is always just about dead on,
plus for backup and just because I know the pickup wont get that last gallon or so in the bottom of the tank I programmed it to less, my tank is stamped 44 gal so I programmed it for 42 gal.
I did drive it one day until it said I had 2.5 gallons left

http://bbgmarine.com/navico-fuel-dat...r-p-15044.html

[DREWTICK]

[Tom Edwards]

Where do you get one of those Fuel Manager things, and how is it wired in?

Thanks. So the round end plugs into the t and row of t's in the console. How does the rectangle end plug in with an only 2' long cable?

[DREWTICK]

just zip tie it, the Tee can go anywhere between the 2 resisters on each end of your NMEA back bone

[Tom Edwards]

So the pod just draws in the info from a wire from the Yamaha cable, then sends it on to the the depth finder thru another wire in that short cable. Nothing plugs into the rectangle pod. Ok, thanks.

[Wackyjig]

When friend’s 721 is on empty he has 10 gallons left. Wonder how accurate my 2018 920 is with smart craft gauge is

My 721 is empty when it says empty..... Don't ask how I know