S&B Fuel Tank Fuel Gauge

[combatgrunt]

Hello,
I installed a S&B 55Gal Tank on my 2022 Ram 2500. I was able to get the fuel tank size reset but the fuel gauge is not working or the DTE as is should. For example it shows I have 1,000miles remaining I have already went 400 I do average 18-20mpg (HWY) most of my driving so the math still don't add up. Has anyone adjusted any other setting to show the gauge correctly? I figure every 13ish Gallons I should move a QTR Tank on the gauge. At this point I'm still showing over full and have the setting for fuel tank size set at 50gallons in size or 189L (DTE did adjust up), I tried adjusting it to 208 DTE moved up but did a test gauge only moved off full just barely at 500miles.

 

[kirk35]

You're at the mechanical limits of the gauge. I had the same issue on my '22 with a Titan 52-gallon tank. I would burn 15 gallons before the needle would start to move off of full. I used HP Tuners to monitor fuel level sending unit voltage as I filled the Titan and the attached image were the results, the S&B will probably be very similar.

 

[2003F350]

The above is the issue everyone who installs a bigger tank comes across. It's not so much the gauge as much as it is the float on the fuel pump assembly - it's only so long, so once it's in the full up position it can't go any higher (as you'll note with the voltage readings kirk gave - it stays maxxed out for quite a while). So yes it's the mechanical limits but not of the gauge but rather the pump assembly itself. To fix this you would need to alter the float arm and position, so that it can read properly. Depending on the fuel pump's design this may or may not be possible, some of them the float arm sensor is molded into the pump housing, others it is basically clamped onto the shafts that hold it all together.