DEF usage !

[Sasquatcher]

I’ve got a 2023 Ram 2500 Bighorn diesel . The truck had over 300 miles when I bought it because it was brought in from another dealership out of state.
The DEF gauge showed about 3/4 full I’m guessing when I drove it of the lot, I dont remember the exact amount. This morning I was at 1220 miles on the odometer.
The DEF gauge was in the red on the last 1/4 so I put 2 1/2 gallons in the tank.
So up to this morning it looks like I used 1/2 tank of DEF to go less than 900 miles. My average mpg is 21mpg for diesel.
I drove 200 miles today and I can see the DEF gauge needle has moved maybe 1/16 .
This doesn’t look normal to me, I’ve never owned a vehicle that uses DEF before so I’d like to know what others are getting out of their DEF with similar vehicles.
Cheers
Colin

 

[diesel_driver_3500]

I get right at 600 mpg of DEF usage when not pulling. Pulling a 5th wheel, I get right at 300 mpg. This is a 2021 3500 SB with the H.O.

I can get you the exact figures, but these are within a few miles per gallon of the hand calculated use.

 

[AH64ID]

I’ve got a 2023 Ram 2500 Bighorn diesel . The truck had over 300 miles when I bought it because it was brought in from another dealership out of state.
The DEF gauge showed about 3/4 full I’m guessing when I drove it of the lot, I dont remember the exact amount. This morning I was at 1220 miles on the odometer.
The DEF gauge was in the red on the last 1/4 so I put 2 1/2 gallons in the tank.
So up to this morning it looks like I used 1/2 tank of DEF to go less than 900 miles. My average mpg is 21mpg for diesel.
I drove 200 miles today and I can see the DEF gauge needle has moved maybe 1/16 .
This doesn’t look normal to me, I’ve never owned a vehicle that uses DEF before so I’d like to know what others are getting out of their DEF with similar vehicles.
Cheers
Colin

Do yourself a favor and go fill the DEF tank at a DEF pump so you know it’s full, then drive until you need to fill it again and do the same. That will give you the most accurate usage.

The gauge is not linear, and moves very quick on the bottom half.

My life average, ‘22 in sig, is 526 mpg DEF. 600-700 mpg DEF empty and ~350 mpg DEF towing. 12.85 mpg life average over 21.7K miles.

Is your 21 mpg hand calc or EVIC?

 

[Sasquatcher]

Do yourself a favor and go fill the DEF tank at a DEF pump so you know it’s full, then drive until you need to fill it again and do the same. That will give you the most accurate usage.

The gauge is not linear, and moves very quick on the bottom half.

My life average, ‘22 in sig, is 526 mpg DEF. 600-700 mpg DEF empty and ~350 mpg DEF towing. 12.85 mpg life average over 21.7K miles.

Is your 21 mpg hand calc or EVIC?

I haven’t hand calculated the mileage but I think I probably should . Thanks .

 

[CharlieL]

I’ve got a 2023 Ram 2500 Bighorn diesel . The truck had over 300 miles when I bought it because it was brought in from another dealership out of state.
The DEF gauge showed about 3/4 full I’m guessing when I drove it of the lot, I dont remember the exact amount. This morning I was at 1220 miles on the odometer.
The DEF gauge was in the red on the last 1/4 so I put 2 1/2 gallons in the tank.
So up to this morning it looks like I used 1/2 tank of DEF to go less than 900 miles. My average mpg is 21mpg for diesel.
I drove 200 miles today and I can see the DEF gauge needle has moved maybe 1/16 .
This doesn’t look normal to me, I’ve never owned a vehicle that uses DEF before so I’d like to know what others are getting out of their DEF with similar vehicles.
Cheers
Colin

Colin, as others suggested figuring out your exact DEF usage will go a long way. I agree it would be a good idea to fill the tank now and refill when it gets down to 1/4 or so. Then you will have good numbers to "hand calculate." For me, "hand calculating" means using the "Road Trip LITE" app (which is free). I have it on my phone for fuel, and on my tablet for DEF. At the moment, my 2022 has 40,800 miles. Of that, 15,000 is towing our 9k fifth wheel. As you can see from the pics, I started tracking DEF at 2,215 miles. The lighter colored entries with "2.50 gallons" are when I didn't fill, but put in a 2.5 jug, usually from Walmart. My average DEF usage is 546 miles per gallon. Obviously that is lower when towing. The worst was 198 mpg when towing into a ferocious headwind! The app tells me that my overall diesel mpg is 13.97. Best ever was 25, worst was 8.1 (which I think was the same time I got the highest DEF usage!!)

 

[deanfx]

Hand calculation, I get about 700 MPG of DEF. When the needle gets really close to red, I add almost four gallons. Maybe 3 gallons and 7/8 of a fourth. lol

 

[Thewookie]

When i picked up my 12k mile 2022 3500 HO in early march and drove it home, Ohio to las vegas, the def tank showed full and i went through 5/8ths in 2200+ miles unloaded.