Gas Gauge for Long Narrow Gas Tank?

I recently purchased a 26' Tolly Craft command bridge and the previous owner retro-fitted a 8' by 16" wide gas tank right down the center of the mid-cabin when he repowered the engine. However, he did not install a gas gauge and when I asked him why he mentioned that a gas gauge would never work with a gas tank this long and narrow ... is that true?

The gas tank is accessible and I would like add a gauge for obvious reasons, but will it register the correct reading in a gas tank of this length?

Thanks in advance for any guidance you can give.

Re: Gas Gauge for Long Narrow Gas Tank?

When do you want to be able to read the gauge?

On the trailer, w/ the trailer sitting approximately level*, to know if you 'need' to buy fuel before you leave the house?

While you're underway, to be able to predict when you need to turn around & return to the dock, or risk running out of fuel?

Afloat in your slip, to decide if you need to swing by the fueling station before you leave the marina?

A long narrow tank will read drastically different fuel levels in each of those scenarios, even though in each, you have exactly 8gal. When the seller said a gauge wouldn't work, I suspect he meant it'd be inaccurate....

If the 1st scenario is when you'll use the gauge, then yep, gauge will work just fine. But only then...

Underway, even w/ baffles, the fuel will slosh to the stern, causing gauge to read more or less full depending on where the float & float arm are in relationship to the shifting fuel.

Unless the boat floats w/ the gas tank level, which seems unlikely, the 3rd wouldn't be a very accurate reading.



*having the trailer roughly level, allows you to check the fuel level w/ repeatable results. If you always check it w/ the trailer roughly level, you should be checking the fuel status while the tank is in a very similar position relative to level, minimizing the variances & inaccuracy...

Re: Gas Gauge for Long Narrow Gas Tank?

Everything JC said above is true and correct^^^^

For a slightly better fuel level sending unit, you should look into a "WEMA" unit...they look like this and read a bit more accurately since they don't use a swing arm...

Re: Gas Gauge for Long Narrow Gas Tank?

jbcurt00 said:

Afloat in your slip, to decide if you need to swing by the fueling station before you leave the marina?

Click to expand...

Thank you for your response. The vessel is not on a trailer, but rather at a slip. Ideally, I would like to know the gas gauge level while at the slip or while floating in calm water - just to give me an idea of range and fuel consumption.

I like the idea of the WEMA unit if I could position it half to three quarters to the front of the tank. Conceivably this should report somewhat accurate readings given that it is not a floating, which would report inaccurate readings when not level ... would it not?

Thanks for the insight

Re: Gas Gauge for Long Narrow Gas Tank?

It's still a float, it's just not on a typical swing arm.

I suppose at the slip, in calm conditions, with the boat generally floating the same, the gauge will work to some degree, probably well enough to judge full, half full, empty.....

Re: Gas Gauge for Long Narrow Gas Tank?

Hello YV

I can just tell you from experience, but standard gas guages on boats are just that, "guages"...you get a general idea of what you have onboard.

If you just want an idea of where youre at, then the sending/guage works ok, but never truely accurate. Keeping track of fuel burn and what you put in is surprisingly more accurate. A FloScan setup solves the mystery of consumption, but at a price...most recreational boats do fine with the standard setup, offshore boats require the latter..