Gas gauge on my 198p

[Lorico]

Fished last Saturday and put in with quarter tank of gas as I wasn't planning on running very far ... ended up doing more running then I expected and ended up back at boat ramp with gas gauge needle laying flat on E which wasn't a big deal as every boat I have ever had hold a few gallons more then what gauge reads . Anyway on way back to house I stopped and filled tank full , Took 22 gallons in a 31 gal tank .


9 gallons left with gas gauge showing empty seems like a lot of difference . Anyone else have the same experience with their 198 or other Ranger RT model ?

[Mechanic Bob]

Because my boat is a squatter, it will show less gas than actual when on the water. On the trailer it is fairly true. That tells me the float is in the front of the tank.

[tcesni]

The gauge on my RT188 is typically pessimistic by 1/4 gallon. If I get nervous I lift the back hatch and can look at the tank but I doubt you can do that. An accurate gauge shouldn’t be that hard.

[jkirch]

I have a 178 with a 25 hp motor . With weight being an issue my dealer said to only keep 6 gallons in it . One day I ran out of gas on the lake because 6 gallons doesn't lift the needle off e . When I filled it back up I watched the needle as it filled . I got passed 6 gallons and nothing happened . When I neared 8 it jumped off e quickly . I now keep much more than that in the tank as I have realized my dad and I are scrawny fellas . I really wish there was an aftermarket gauge that I knew would fix that problem.

[Kdixer]

It will surprise you how many gallons are required to fill to just 1" from the bottom of a rectangular fuel tank (depending on actual width and length). Then add in the fact that most fuel senders do not read off of the exact bottom of the tank due to most boat components being generic in nature. The sending unit may be 1" off the bottom and the float may need to be submerged almost 1/2" to 1" before it actually begins to float.

Example:
Width = 16"
Length = 44"
Volume at 2" fill level = 1,408 cubic inches or 6 gallons

Add another 1" because most fuel floats do not start to lift as soon as fuel hits the bottom and you are looking at 9 gallons before the fuel is detected by the sending unit.

[Johnnyred]

good one,Kdixer. I have never had a boat with a fuel gauge worth a d#$%nm at ready levels when it is getting low.

[tin wacker]

my 188 is 1/4 tank off

[Lorico]

It will surprise you how many gallons are required to fill to just 1" from the bottom of a rectangular fuel tank (depending on actual width and length). Then add in the fact that most fuel senders do not read off of the exact bottom of the tank due to most boat components being generic in nature. The sending unit may be 1" off the bottom and the float may need to be submerged almost 1/2" to 1" before it actually begins to float.

Example:
Width = 16"
Length = 44"
Volume at 2" fill level = 1,408 cubic inches or 6 gallons

Add another 1" because most fuel floats do not start to lift as soon as fuel hits the bottom and you are looking at 9 gallons before the fuel is detected by the sending unit.

Thanks for the math and explanation .... Guess it's like every other new boat I've ever had - Gonna have to learn all the quarks and perks by using it

[Lorico]

my 188 is 1/4 tank off

As in 1/4 tank full when it reads empty ?

[bassfisher444]

Pretty normal on most boats and vehicles.

[Bill Reynolds]

my 188 is 1/4 tank off

Mine is too, won’t go much past 3/4 when full. I fiddled with it and worried about it for about a year then installed a MercMonitor (for another reason).
I reset gallons used at each fill up and when the gauge is approaching empty I check the gallons used. When the gauge has been on empty for a while it normally takes about 16 gallons to fill up.

[Lorico]

Mine is too, won’t go much past 3/4 when full. I fiddled with it and worried about it for about a year then installed a MercMonitor (for another reason).
I reset gallons used at each fill up and when the gauge is approaching empty I check the gallons used. When the gauge has been on empty for a while it normally takes about 16 gallons to fill up.

How accurate is MercMonitor ?

[Bill Reynolds]

How accurate is MercMonitor ?

it seems to be very accurate. I don’t know how it calculates fuel used, but it must be done In the ECM because I do not have a separate inline flow meter.
I overdosed on stupid pills during a trip to TOHO and locked down to Kissimmee on a partial tank of fuel before it occurred to me that I also had to drive back. By monitoring the fuel burn rate on the MercMonitor and adjusting speed and trim to get the most efficient fuel usage, I was able to make it back to TOHO.
The MercMonitor showed that I had burned 20.9 gallons and it took 21 gallons to fill it up. (20 gallon tank)

[Lorico]

That's cutting it close ! Do you know if the Vessel View mobile uses the same technology to figure fuel rate ?

[Bill Reynolds]

I can only guess but I can’t imagine why it would not.

[Mechanic Bob]

Why not fill your tank? Will also help keep condensation out too. Marine Safety course tells you to use the 1/3 rule. 1/3 out, 1/3 back, 1/3 third in reserve.

[Lorico]

Why not fill your tank? Will also help keep condensation out too. Marine Safety course tells you to use the 1/3 rule. 1/3 out, 1/3 back, 1/3 third in reserve.

Am assuming this post is directed towards me so ... Most of the time I do But not always . My interest is more in what travel distance I can get with the fuel I have. Am fishing a tournament on Red River in Oct and can for see some long runs. Being that I live right on the lake here for the most part I don't run far or if I want to fish the far end of the lake I trailer , haven't had a chance to make long runs and without making a 50+ mile run to see what my gas consumption is ( not to mention the cost of such a test ) have been trying to get a feel for the factory gauge.

White River Marine did send me a 250.00 gift card to Bass pro , don't know if it was for buying my boat or for them dropping the ball on the paint issues I had with it ? Either way I invested that card in a Vessel View mobile which I installed yesterday so I'll spend some time with that and see how that works . Have read some reviews in the VV and some have said if you don't have a cell signal that system doesn't work so I'll be back to gas gauge. In the mean time I'll be working on figuring it out

[Mechanic Bob]

Yes it was directed at you.
I made a 30 mile run with 10 miles at 2200 rpm and used less than 6 gallons of gas. I will add that I was also going against the tide for 10 miles of that trip.

[GeauxTide]

When I got a Vessel View Mobile, I no longer paid attention to the gas guage. In over 40 years of boats, none have had a remotely accurately gas guage. Keeping my boat in a boat port, I keep the tank full of 89 Octane and treated with Startron Enzyme and Ring Free. I know the rating, but my Opti snorts and farts with 87.

[Lorico]

Well Vessel View not only proved how bad my gas gauge was lying to me but also my Tachometer ! Factory installed tach showed I was running 6000 RPM with current prop WOT , VV showed 5450 which explains some performance issues I've been having