Def Fluid

[Npd9769]

I have a 2019 Laramie Longhorn and I have two questions. How big is the def fluid tank and I have to refill mine about every 1,000 - 1,200 miles, is this common. Only about 200 miles of that is towing. My buddy owns a 2019 Ford F-250 and he says he doesn't use nearly that much def fluid.

 

[nytmare]

Some of the 2019s have/had issues with accelerated DEF usage. I believe Ram has a recall, TSB, or something out on it as some folks have had their PCMs reflashed with updated software to resolve the issue. You may want to check to see if your truck needs an update.

 

[tjfdesmo]

I think the tank is 5.5 gallons??? When you say you have to refill is the DEF tank empty, as in you are getting the "miles to derate" warning? My '19 has averaged approx 800 MPG/DEF overall, and more in the 500 or so range when pulling heavy. Others go by fuel used, which translates to about 2% of fuel used. As stated, some early build trucks need reflashed.

 

[Ricky Herring]

never refilled mine yet, i have 2500 on my 2019 still at 1/4 tank.

 

[WY-Dave]

5.5 gals. The refills are 2.5 so when I hit 1/2 I fill up. About every 2k miles I refill (2.5 gals)

 

[RamCares]

I have a 2019 Laramie Longhorn and I have two questions. How big is the def fluid tank and I have to refill mine about every 1,000 - 1,200 miles, is this common. Only about 200 miles of that is towing. My buddy owns a 2019 Ford F-250 and he says he doesn't use nearly that much def fluid.

Hi @Npd9769 - please do not hesitate to follow up with us via PM on this. I would be happy to see if there is anything associated with your VIN!

Mark
RamCares

 

[mtnrider]

Like mentioned, 5.5 gallons. Also, the gauge is not linear so it will stay "full" forever before it starts to move.
I haven't actually measured how much DEF I use but if you are using 5 gallons per 1000 miles not towing that seems high. I don't track it but I'd guess I add a 2.5 gallon jug every 3000 ~miles when not towing?

 

[moparguy62]

I'll be taken a maiden voyage with my 2019 towing 16k thru mountains at end of March I'll let you know the consumption.

 

[Orlando70]

commuting to work I get about 1000 MPG. pulling and enclosed trailer @ 8000 lbs on 2000 miles round trips @ 400 MPG

 

[WY-Dave]

5.5 gals. The refills are 2.5 so when I hit 1/2 I fill up. About every 2k miles I refill (2.5 gals)

16750, 18856 & 20752 miles

 

[Blazin383]

I recently towed my 10,500 lb 26' toy hauler 1900 mile round trip from WA to Moab UT and back, and I had to fill the DEF tank twice. I filled it at 1/4 tank or a little less, but it sure seemed like it used a lot of DEF, More than I expected. The truck averaged 11 mpg for the trip.

 

[MO_CPA]

I have 900 miles on my truck and just below 3/4 of a tank of DEF.

 

[WY-Dave]

16750, 18856 & 20752 miles

& 22705

These are 2.5 gal fills (1 jug) @ half reading

 

[Elkman]

Check how many gallons of diesel you have burned and not the miles driven. DEF consumption should be 1% to 1.5% of the fuel consumption so 5 gallons of DEF should last for at least 333 gallons of diesel fuel. Even at 15 mpg the 5 gallons of DEF should be enough for 350 gallons of diesel or over 5,000 miles of driving. Of course when towing a heavy trailer and getting 10 mpg the DEF may last for 3500 miles.

The amount of DEF injected depends on the PCM programming and the NOx sensor readings it gets. Bad programming or a bad NOx sensor will result in far too much DEF being injected into the exhaust stream. I experienced a great increase in DEF consumption with my truck some months before the NOx sensor failed to the point where it generated a code.

 

[HDGoose]

With my 2013 Ram 2500 I have towed the 5th wheel down to south florida and back, about 1500 miles, on less than 1 tank of DEF. Get the dealer to look at it. Your usage seems excessive. At 11 mpg you are using way too much DEF.