Gas Tank Size - Is it Accurate?

[SkeeterJackson]

I have a 2021 big horn with a 23 gallon gas tank. First of all, for anyone who is purchasing a new truck, get one with a 33 gallon. I feel like I have to fill up every 4 hours. It's terrible!

Ok, so I usually run down the gas anywhere from 20-50 miles to empty. This equates to about 1/8 of a tank left. I have never filled more than 18 gallons of gas in this thing. This time, I purposely waiting for the range to get down to 10 miles and the guage was less than 1/8, I would guess 1/16 or so. I was able to put in 18.7 gallons. I even topped it off as much as I could. Shouldnt I be able to put it way more? Is my tank really 23 gallons??

 

[mikeru82]

This has been discussed many times. In my experience with Ram trucks, there seems to be about a 4 gallon discrepancy between what I could add and the advertised tank size. I'm sure the tank is actually 23 gallons, but I suspect that's with it totally empty, no fuel pump or sending unit, all hoses empty. What you're seeing is pretty normal. Just drive and enjoy your truck. As a side note, it's not a good idea to keep adding fuel once the pump shuts off. And that's suspected in causing issues with fueling further down the road. Also, I totally agree with you about the 23 gallon tank being too small. It's one of the reasons I traded in the 2020 Laramie I used to own. I'm much happier with the 33 gallon tank.

 

[JF19Longhorn]

Not sure about the 23, but I have the 26 and I've managed to put 24.2 gallons in it trying to make it across the state line (gas is MUCH cheaper in Jersey than PA). Guessing that's pretty close to empty. I do not recall what the MTE was, but I know the low fuel light came on.

 

[SkeeterJackson]

This has been discussed many times. In my experience with Ram trucks, there seems to be about a 4 gallon discrepancy between what I could add and the advertised tank size. I'm sure the tank is actually 23 gallons, but I suspect that's with it totally empty, no fuel pump or sending unit, all hoses empty. What you're seeing is pretty normal. Just drive and enjoy your truck. As a side note, it's not a good idea to keep adding fuel once the pump shuts off. And that's suspected in causing issues with fueling further down the road. Also, I totally agree with you about the 23 gallon tank being too small. It's one of the reasons I traded in the 2020 Laramie I used to own. I'm much happier with the 33 gallon tank.

Thanks for the info. What you said makes sense with the fuel pump and sending unit. I don't typically top off the tank, but I currently am having the issue that several others are having with the fuel pump stopping every half gallon or so. I am currently waiting on a new tank for that fix. I also tried to get an upgrade to the 33 gallon and I would pay the difference, but the service manager couldnt make it happen. I wish I would have paid more attention to the tank size before purchase.!

 

[Dookie]

I found something interesting today, a post from the 33-gallon tank swap thread said if you have a 26-gallon tank, your Fuel capacity setting in the BCM should be at 98 liters (26 gallons = 98.4207 liters) so I looked at my Alfa file and it states Fuel Capacity (36-290 L): 93.000 Liters (93 liters = 24.568 gallons).

I think RAM set it up like that to have some cushion or reserve fuel to avoid people running out. Right now my low fuel light comes on at 50 miles DTE and the gauge is showing 1/4 tank. I plan to use Alfa and change it to 98 liters as my window sticker and build sheet both show a 26-gallon fuel tank and see how that affects the gauge and DTE miles along with low fuel light.

 

[SkittleRam]

I have put about 31gl in my 33gl tank.

 

[HemiDude]

I found something interesting today, a post from the 33-gallon tank swap thread said if you have a 26-gallon tank, your Fuel capacity setting in the BCM should be at 98 liters (26 gallons = 98.4207 liters) so I looked at my Alfa file and it states Fuel Capacity (36-290 L): 93.000 Liters (93 liters = 24.568 gallons).

I think RAM set it up like that to have some cushion or reserve fuel to avoid people running out. Right now my low fuel light comes on at 50 miles DTE and the gauge is showing 1/4 tank. I plan to use Alfa and change it to 98 liters as my window sticker and build sheet both show a 26-gallon fuel tank and see how that affects the gauge and DTE miles along with low fuel light.

Now Following

 

[devildodge]

The fuel is also used to cool the pump.

And the tank is long. So on a hill the pump will starve for fuel.

Which is why they make you think you are almost out of gas when you are not.

One...to keep you from running out of gas and two...to let the fuel pump live

 

[bigdodge]

with all the nooks and crannies, it's no wonder the tank can never be filled all the way

Fuel Tank.

Diagram of OEM Fuel Tank. Contains Tank. Fuel. [33 gallon fuel tank] for Fuel Tank. Fits 1500.

www.factorychryslerparts.com

 

[kdoublep]

I just took my 26 gal tank down to 38 miles left. I was able to pump about 24 gals to fill. My low fuel light comes on at 50 everytime.

 

[SD Rebel]

The fuel gauge is very conservative because they know people will run them down on occasion.

I have a 26 gallon, and I rarely get more than 21 in there if I fill up shortly after the light turns on. Factor in the miles left on the computer, I should have 3 more gallons left, that would bring me to 24 gallons. 2 gallons off the mark.

However, I have confirmed I do have a 26 gallon tank, so the difference is likely in an extra gallon or so of leeway on the gauges and trip computer and also in the fuel tank system that's part of the tank.

 

[HemiDude]

with all the nooks and crannies, it's no wonder the tank can never be filled all the way

Fuel Tank.

Diagram of OEM Fuel Tank. Contains Tank. Fuel. [33 gallon fuel tank] for Fuel Tank. Fits 1500.

www.factorychryslerparts.com

LOL seems like that diagram has waaaaaay too many lines it

 

[Dookie]

Now Following

Here is the post made by @Dixit
Honestly folks, easiest way to know what you got is hookup an OBDII ELM327 based scanner, load AlfaOBD, and pull up configuration, you will see what it says for fuel tank size in liters. If you got a 26gal it will state 98 liters. If you have the 23gal it will state 87 liters. 33gal will show 125 liters (which is what I set it to once I swapped the tank to have Distance to Empty correct).

Even the free version of AlfaOBD should work to do this.

Here is a snapshot of whats youd see, its under Vehicle Config 3
Vehicle Config 3:
Police Lighting Feature: Not set
Power Lift Gate Present: Not set
Power Right Sliding Door Present: Not set
Power Left Sliding Door Present: Not set
RKE System Present: Set
Sunshade Present: Not set
T-Case Type: Not present
Fuel Capacity: 125 Liters
Wheel Base: Not defined
FOBIK Safe Enable: Set

 

[IvoryHemi]

For me when the Range hits 10 mi/Low there is about 2 gallons left in the tank.

 

[SnowBlaZR2]

I have a 2021 big horn with a 23 gallon gas tank. First of all, for anyone who is purchasing a new truck, get one with a 33 gallon. I feel like I have to fill up every 4 hours. It's terrible!

Ok, so I usually run down the gas anywhere from 20-50 miles to empty. This equates to about 1/8 of a tank left. I have never filled more than 18 gallons of gas in this thing. This time, I purposely waiting for the range to get down to 10 miles and the guage was less than 1/8, I would guess 1/16 or so. I was able to put in 18.7 gallons. I even topped it off as much as I could. Shouldnt I be able to put it way more? Is my tank really 23 gallons??

I have a 23 gallon tank (happy with it), and at right about 1/2 a tank on the gauge I put about 12 gallons in it. I haven't run it down much below 1/2 a tank yet, though.

 

[mikeru82]

I have a 23 gallon tank (happy with it), and at right about 1/2 a tank on the gauge I put about 12 gallons in it. I haven't run it down much below 1/2 a tank yet, though.

You should run on the bottom half of the tank instead of the top half. That way you'll save almost 80 pounds of payload, and you'll always have your compressor with you.

 

[SnowBlaZR2]

You should run on the bottom half of the tank instead of the top half. That way you'll save almost 80 pounds of payload, and you'll always have your compressor with you.

I'm actually looking at one of these. Then I can tow the truck with the trailer and get unlimited MPG!

 

[mikeru82]

I'm actually looking at one of these. Then I can tow the truck with the trailer and get unlimited MPG!

But wouldn't that be putting the cart before the horse...er...truck?

 

[Dookie]

I had a flat tire before, but it was only on the bottom so I just flipped it over.

 

[Amazing93]

Wow I can't imagine a truck with a tank that small. I wonder why they don't just build em all with the 33.