Truck has a 27 gallon tank.

 

The diesel trucks from 2011-2016 have one of two tanks depending on cab and bed designs. The short bed trucks came with 26 gal tanks and the long bed came with 37.5 gallon tanks. There are variations depending on cab also but only these two tank sizes.

The accuracy of the fuel gauge might be in question as well as the DTE shown. I ran mine down to where the DTE showed less than 5 miles to empty prior to installing the larger Titan tank. When I removed the stock tank, it still had approx 5 gallons of fuel left in the stock tank.

If you feel it has a wrong tank installed or programmed for your truck, you can do a few things.

1) - You might want to check to see what tank size is programmed into the instrument cluster (IPC). If you have access to FORScan and an OBDII adapter, you can check and/or change the tank size if incorrect. Or, you can go to a dealer and ask them to check what tank size is programmed.

Here is a list of programmable parameters for various modules on your truck contained within this spread sheet. Do not make random changes should you gain access via FORScan.

https://docs.google.com/spreadsheets/d/17e_PIE5s3H266gWgSG7xdFLGKxIr1-K_RwrIx4qIAtI/edit#gid=0

2) - My suggestion for you is to get an approved 5 gal fuel container, fill the truck and 5 gal container with diesel, reset Trip "A" to zero it out, drive the truck till your gallons used, as shown by Trip "A", approaches 26 gallons.

If the truck runs out 5 gallons or more before 26 gallons are used, you might have some sort of a tank problem. You will have the container of diesel to prevent being stranded.

If you are approaching 26 gallons used, then you know the truck has a 26 gallon tank. You can add the fuel from the container and then finish fueling the truck.

Personally, I do not rely on the Instant MPG nor the DTE (distance to empty) as shown on the center display of the instrument cluster. I pay attention to the fuel gauge and Trip "A" to know how many gallons I used and gallons left.

 

If the truck runs out 5 gallons or more before 26 gallons are used, you might have some sort of a tank problem. You will have the container of diesel to prevent being stranded.

Isn't running out of a fuel a very bad idea for most modern diesel motors? Or is that more for HEUI? Would it even be worth the risk?

 

Shortbed model is 26 gallon. Put a 50gal Titan in mine. What were they thinking 26 gallon for a SD Truck shezzz!!

 

filled up about 15 times and the gauge is only reading 20 gallons of fuel. To clarify - the estimated miles and gauge are working off the assumption there is a 20 gallon tank installed.

I read this multiple times and it does not compute... if you are going the handle clicks then you are getting a lot of foam.

 

Thanks for the information everyone! Will be upgrading the tank as suggested.