Gas Gauge

[MarkCB220S]

Hi....I am new owner of 2019 Cobalt 220S which has a 52 gallon gas tank. I have only filled the gas once since owning. I filled the tank when the gas gauge read 64% and to my surprise I was able to fill it with 42 gallons of fuel which would mean the gauge should have read roughly 20%. I get it gas gauges on boats are not super accurate but can someone tell me if the gauge happens to have a light indicator when close to running out or what percentage of fuel on gauge I should use as my "time to get gas" indicator so I don't run out? My boat is slipped and there is gas on the lake but I prefer to pull it out and fill the tank at a more reasonable price! I rather only take it out on "as needed" bases.

Thanks

[MarkCB220S]

To add.....I have the 6.2L 300hp V8 so it consumes a lot of gas quickly so definitely don't want to push it......

[sailor55330]

I have never personally seen a low fuel light on a boat's gas gauge. My R3 does not have one. You are correct, they are not the most accurate devices. The sender unit is basically a float on a rod that goes up and down with the fuel... when the boat rocks or rolls, fuel shifts and so does the readout. I did have a sender unit that behaved like yours... Is it still under warranty? Sender units are cheap and easy, but still something you have to deal with. Can you track your usage based on hours until you get things squared away?

[MarkCB220S]

Thanks for quick reply....I'm guessing nothing is wrong with it and just something I will need to get accustomed too as I continue to learn the quirks of the boat as the new owner. I am hoping someone out there may have same make/model and merc who could provide some tips/tricks. I will develop my own process but I am getting low roughly 40% now and don't plan to pull it out of the water until the 4th of July to take it to my brothers cabin...I was hoping to make it on the fuel until then to fill it.

[Norris_Boating]

So if you look through your owners manual (Volvo manual I believe) there is a way to calibrate the gas gauge. I believe through the interface near the throttle. Been a couple years since I looked at it so can't remember exactly.

[sailor55330]

It could be a simple as a stuck float. Pulling the sender unit is usually 5 bolts and is straight forward--just don't over torque when tightening. It might be worth pulling the unit to see if it's moving freely. If it was bent on installation then that could throw the gauge off--just a thought. Does it read differently on the trailer vs in the water?

[CobaltDeadHead]

My boat is obviously older and I have a Merc, but the guage is about as worthless as tits on a bull. I just keep a mental note and have a rough idea of how much I've used. I've become pretty accurate at estimating when I go through 30 gallons. Sometimes that amount reads closer to a half tank, others closer to a quarter.

[Stagdad]

My 220s had the same issue, Gauge indicated 1/2 full and I put almost 40 gallons in at fill up. I hauled it back under warranty to the dealer and they allegedly calibrated it, but it still is off. I just tell myself that 1/4 tank is refill time. As for more accuracy your lake water temp gauge will read within 10 degrees of actual temp and air temp will read within 20 degrees!

[Krob1114]

Similar experience to CobaltDeadHead and Stagdad.
I've owned two boats, halve tank means a quarter tank. Quarter tank means time to buy gas.

[Big Block Power]

I've been pretty lucky on this boat. The speedo and fuel Guage are dead on.

[skno]

Similar experience to CobaltDeadHead and Stagdad.
I've owned two boats, halve tank means a quarter tank. Quarter tank means time to buy gas.

Exactly!

[MarkCB220S]

Thank you all.....my float seems find as the fuel level does jump around. From what I can tell the 1/4 tank "time to fill" is about right and what I will go with as it sounds like there are no other good solutions. Just something you need to get feel for and each boat is a little different.

[Kyboater]

My Garmin gauge shows 105% after a fill up. It remains there until it drops to 80% or so. I feel once rooms is in the tank the sloshing occurs and the gauge is bouncing all over the place but once we park in a cove or idle back to the ramp it is fairly accurate. We trailer and I fill up after each outing so I already have a good idea of how much fuel we used. As for a low fuel light. It’s only happened once, but if the level gets below 10% the entire gauge turns bright red.

[Mike in SC]

My son filled our tank at 1/4 and put 30 gallons in. With a 50 gallon tank that meant 20 gallons remaining rather than 12.5...today I filled it at 1/2 and...30 gallons. Am hoping to not run out of fuel, but wishing I had better data!

[Elkhunter2372]

My son filled our tank at 1/4 and put 30 gallons in. With a 50 gallon tank that meant 20 gallons remaining rather than 12.5...today I filled it at 1/2 and...30 gallons. Am hoping to not run out of fuel, but wishing I had better data!

Hey Mike, new boat here too so I'm still playing with my gas gauge. I filled it 3 weeks ago when we headed to Lake Powell. Gauge was at 47% and I put in 27 gallons. I filled it twice down there that week...letting the gauge drop to around 1/4 tank...I was putting in 6 cans at roughly 5.5 gallons each....so 33 gallons.

Headed to Lake Powell again last week....gauge showed 33% and I put it 32 gallons to fill it. Filled twice again on the lake and put in same 6 cans of 5.5 gallons each.

Mine appears to be tracking fairly accurate. That being said, every boat is different and the best advice you've been given, regardless, is that 1/4 tank on the gauge means find fuel soon. That has always been my protocol with any boat I've had. Typically the top "half" of the tank on a boat is bigger than the bottom "half".