50 Gallon Fuel Tank

[Brutal_HO]

You can adjust the tank size, but only up to a certain amount. So you can go up to I assume the biggest factory tank of 50 gallons but not beyond that.

My factory 50 gallon setting is 184 liters. The value will accept up to 194 liters.

The full (91%), DTE warning (8%), and empty (2%) values already in the BCM should not need to be changed unless your DTE is higher for some reason. No clue why the Full is 91%, It appears it's just telling the gauge what to show.

 

[Will_T]

Does anyone know how much ground clearance you lose by switching to say the S&B 52 gal tank compared to the 31 gal stock tank?

I am not sure if it is the same for the S&B but I have the Titan. On their website it says the tank: "is approximately only 2” below the frame rail." Mine is actually about 2-1/2 below the frame at the lowest point. The OEM was a bit above the rail if I remember correctly. So, I would estimate the Titan is at least 3" closer to the ground than the OEM. I don't think the OEM tank was the where the original clearance was measured by so just because the Titan is 3" lower than the OEM doesn't necessarily mean I lost 3" of clearance under the truck. Clearance from the tank was lost, but as a hypothetical example, if the original clearance of the truck was measured from some other lower point of the truck other than the OEM tank, and that point was 2" lower than the OEM tank, then...... it gets complicated.

I think of it as the fuel tank clearance on my truck was reduced by 2-1/2 to 4" maybe. But clearance from whatever was the original low point under the truck probably did not change much at all. The tank is definitely closer to the ground than the OEM though. I would be more concerned if I took the truck seriously off road. But even though I am sometimes on very rough gravel roads, clearance is not an issue. But if you are driving over stream beds or boulders, then I would be concerned. Titan did tell me that in all their years they had only heard of one of their tanks being damaged in that way.

 

[delmoniCO]

My factory 50 gallon setting is 184 liters. The value will accept up to 194 liters.

The full (91%), DTE warning (8%), and empty (2%) values already in the BCM should not need to be changed unless your DTE is higher for some reason. No clue why the Full is 91%, It appears it's just telling the gauge what to show.

I missed where this setting is in Alfa. Please share where to change full (91%) to something else.

 

[Brutal_HO]

I missed where this setting is in Alfa. Please share where to change full (91%) to something else.

Why do you want to change it?

It doesn't matter much if it's s 32 gallon or 50 gallon.

91% of 50 is 45.5
91% of 32 is 29.1

Something in AlfaOBD must have changed.

I used to have these values:

Cluster Configuration:
Fuel Tank Calibration, Full: 91%
Fuel Tank Calibration, Empty: 2%
Fuel Tank Calibration, LFW: 8%

Now it shows this:

Cluster:
___________________
Fuel Tank 1 Calibration, Full Datum for Fuel Voltage 1: 0
Fuel Tank 1 Calibration, 3/4 datum for Fuel Voltage 1: 0.000
Fuel Tank 1 Calibration, 1/2 datum for Fuel Voltage 1: 0.000
Fuel Tank 1 Calibration, 1/4 datum for Fuel Voltage 1: 0.000
Fuel Tank 1 Calibration, LFW datum for Fuel Voltage 1: 0.000
Fuel Tank 1 Calibration, Empty datum for Fuel Voltage 1: 0.000
Fuel Tank 1 Calibration, E Stop Datum for Fuel Voltage 1: 0
Fuel Tank 1 Calibration, Empty: 2%
Fuel Tank 1 Calibration, LFW: 8%

 

[Brutal_HO]

I missed where this setting is in Alfa. Please share where to change full (91%) to something else.

Why do you want to change it?

It doesn't matter much if it's s 32 gallon or 50 gallon. I believe every BCM is set to 91% regardless of fuel tank size.

91% of 50 is 45.5
91% of 32 is 29.1


I must have been
Cluster:
___________________
Fuel Tank 1 Calibration, Full Datum for Fuel Voltage 1: 0
Fuel Tank 1 Calibration, 3/4 datum for Fuel Voltage 1: 0.000
Fuel Tank 1 Calibration, 1/2 datum for Fuel Voltage 1: 0.000
Fuel Tank 1 Calibration, 1/4 datum for Fuel Voltage 1: 0.000
Fuel Tank 1 Calibration, LFW datum for Fuel Voltage 1: 0.000
Fuel Tank 1 Calibration, Empty datum for Fuel Voltage 1: 0.000
Fuel Tank 1 Calibration, E Stop Datum for Fuel Voltage 1: 0
Fuel Tank 1 Calibration, Empty: 2%
Fuel Tank 1 Calibration, LFW: 8%

 

[delmoniCO]

Why do you want to change it?

It doesn't matter much if it's s 32 gallon or 50 gallon. I believe every BCM is set to 91% regardless of fuel tank size.

91% of 50 is 45.5
91% of 32 is 29.1


I must have been
Cluster:
___________________
Fuel Tank 1 Calibration, Full Datum for Fuel Voltage 1: 0
Fuel Tank 1 Calibration, 3/4 datum for Fuel Voltage 1: 0.000
Fuel Tank 1 Calibration, 1/2 datum for Fuel Voltage 1: 0.000
Fuel Tank 1 Calibration, 1/4 datum for Fuel Voltage 1: 0.000
Fuel Tank 1 Calibration, LFW datum for Fuel Voltage 1: 0.000
Fuel Tank 1 Calibration, Empty datum for Fuel Voltage 1: 0.000
Fuel Tank 1 Calibration, E Stop Datum for Fuel Voltage 1: 0
Fuel Tank 1 Calibration, Empty: 2%
Fuel Tank 1 Calibration, LFW: 8%

Thanks. I'll check this out today. I'd like the gallons for the warning behavior to be closer to stock.

 

[Brutal_HO]

Thanks. I'll check this out today. I'd like the gallons for the warning behavior to be closer to stock.

Stock is 8% and 2%. Pretty sure it's the same no matter the tank size.

 

[delmoniCO]

Stock is 8% and 2%. Pretty sure it's the same no matter the tank size.

Yes but I mean gallons not percentage. I'd set Empty to 1% and the warning to 5%. At the top Id change Full from 91% to 95%

 

[Gus]

I have a 14 so changing the capacity does nothing for me. For those of you math gurus would changing the percentages give me a more accurate reading? Or i should say I would like for the fuel gauge to operate more like stock. Right now when the fuel light comes on I guesstimate I have 10 gallons left.


Sent from my iPhone using Tapatalk

 

[DesertLawman]

Ok tank is in and filled. Nice seeing over 800mi on the dash. I wouldn’t recommend doing in the driveway while the snow is melting…
Another question…how do I get the bypass cable disconnected?? I’ve got the obd2 disconnected but the other two cables will not come out. What am I missing?? And thank f I left those connected but tied up the bypass obd2 could the dealer still tell it’s there with a scanner?? I’ve got an inspection tomorrow of course. Thanks!

Did you have to have the computer recalibrated for the 50 gal tanks for miles to empty or does it adjust itself?

 

[delmoniCO]

Yes but I mean gallons not percentage. I'd set Empty to 1% and the warning to 5%. At the top Id change Full from 91% to 95%

8% and 2% are apparently the lowest supported values on Alfa.

 

[DesertLawman]

Thanks GeekToad. Hope you can find the part number.

For the question on the tank size by other members - from my quick research looking at different versions on the Mopar online parts places, I believe that the Cummins trucks it is 50 Gal and the 48 Gal is on the gasser. The problem is that the 50 gallon tank isn't on any of the parts diagrams yet. I also noticed that the chassis frame trucks look like they have two tanks with the rear tank being 50 gal.

I found the 50 gal mopar tank and ask what it would cost to install it. Unfortunately, you just cant add this tank to replace the 32 gal stock tank. You need all new parks and mounting hardware. Although the tank was cheaper than the Titan, buying all the new parts and straps would increase the cost to match the Titan, which uses all the original stock parts from the 32 gal tank. I went with the Titan

 

[mlink]

I ordered my 3500 Limited CC LB with the 50 gal tank. I also bought the Transfer Flow 70 gal Toolbox/Aux Tank for 120gal total capacity and heavy 5th Wheel towing range of about 1200 miles. (CT to Myrtle Beach w/30+ gals leftover).

The Transfer Flow uses a module which plugs into the OBDII connector where it monitors the level of the OEM tank and the Aux tank. At select intervals, it uses this info to pump fuel from the Aux to OEM through the OEM vent line until the two tanks are in balance. There is an App for phone where you can monitor if you want.

On my setup, I just watch the main tank gauge which lets me pass all those rest area fuel stations I used to stop at…

 

[loveracing1988]

I found the 50 gal mopar tank and ask what it would cost to install it. Unfortunately, you just cant add this tank to replace the 32 gal stock tank. You need all new parks and mounting hardware. Although the tank was cheaper than the Titan, buying all the new parts and straps would increase the cost to match the Titan, which uses all the original stock parts from the 32 gal tank. I went with the Titan

I thought all you needed was an extra strap because the 50 gallon had 3 compared to the 2 on the 32 gallon.

 

[St.Pete Ron]

I thought all you needed was an extra strap because the 50 gallon had 3 compared to the 2 on the 32 gallon.

The 3rd strap is on the 60 gallon tank.

 

[H3LZSN1P3R]

The 3rd strap is on the 60 gallon tank.

There is no 60 gallon tank…

 

[St.Pete Ron]

There is no 60 gallon tank…

The S&B has a 60, I thought it was the titan.

 

[H3LZSN1P3R]

The S&B has a 60, I thought it was the titan.

He is referring to the mopar factory tank i believe

 

[DesertLawman]

I just added the 55gal titan tank to my 3500. I will soon get the Alphaobd so I can correct the DTE reading. I have heard that there have been some problems updating the DTE to anything over 194 liters, causing the fuel gauge to go to zero. I need to update mine to 208 liters to reflect the 55 gals. Has anyone swapped out their sending unit to the 50gal and if so, did it solve the gauge problem?

 

[DesertLawman]

I thought all you needed was an extra strap because the 50 gallon had 3 compared to the 2 on the 32 gallon.

I had an installer research this for me and a lot more is needed to add this tank if not from the factory. It made it not cost effect so I want with the titan