Low Fuel Warning - 09 RZ2

[naterbme]

I'm certain this has already been discussed but I can't seem to locate it the past forums.
I recently purchased my first boat - 2009 RZ2 - and its been a fast learning curve!

My issue - we had 40% fuel when we started last night and 30 minutes later it started showing the "Low Fuel Warning". We were running around 16 with taps at 4 and pulling a knee boarder. Not wanting to push the situation, we loaded up and headed home. On the way home, we stopped and filled up but I was only able to put 32 gallons in it. Seems like that would be pretty close to the reading when we started (in the 30-40% range) but why would the low fuel warning start when there is still 10-15 gallons of fuel left?

Again, I'm pretty new to the owner thing. Please be kind!http://www.tigeowners.com/forum/images/icons/icon6.png

[boardman74]

Boat fuel gauges suck. They are notoriously inaccurate. They bounce around as your boat does.

They are like motorcycle gauges and generally can't be trusted. Best thing you can do is figure out roughly what your boat burns per running hour on the meter. Figure it out just like you would MPGs in a car. Then you know within a few gallons where you are at all the time. Also you need to figure out what your tank holds. Don't trust the published specs, take a look at the top of the tank. Then figure around 80-90% of that is usable. The gas gauge is more of a "guide" than an actual gauge like in your car.

[naterbme]

Thanks boardman, do you have any idea what the low warning set point would be? In other words, how much fuel is left once you see the warning indication? I would assume that's the same on most, as a general setting?

[boardman74]

Minus in the Tige Touch I have never had a boat that had a low fuel warning.

I think in the Tige Touch its around 20%. Usually in most items its around 1/8 of a tank.

[BCRider]

When my boat gets around 30-40% I always add fuel. My boat will read 99% next to forever and all of a sudden just drop. Top last forever and once it's below 50 it goes down fast. I can usually get about 3 trips out on the water before I have to refill depending on how much we are running.

[ericinmich]

As others have said, you can't trust a boat fuel gauge. Meaning you have to learn what yours is telling you, 40% doesn't mean 40% fuel level like you think it should.

I did fuel level SW/Cal on auto's a while back (OK, 20 yrs). In a car, the mfg controls the shape of the tank, has baffles, the car generally runs level. We had logic to buffer/average the reading, used ign state to deal with refilling, etc. Then spent a lot of time calibrating to get it as accurate as possible.

Boats have rectangular tanks with flat bottoms, longer fore/aft, more sensitive to boat altitude which changes a lot. I don't think they have baffles to control slosh, etc.

My 22Ve stays on 99% forever, then drops rapidly. I have a google drive sheet for every fill up, write down the hours at fill up, % reading, gallons put in, etc. Bottom line, get used to how many hours between fills (of course hours pulling surfer are different than hours at idle). I fill up shortly after it goes below 50%. Running out of gas on a lake sucks.