How Much DEF Are You Using In Miles?

[HPSimpson]

My diesel truck used 5 gallons of DEF in 4207 miles which I think is way too much, I went to my dealer again which I new was waste of time, his answer that's on the high side but close to normal for your truck because you tow a boat use will use more. I said that is bull stored, I quietly look at dealer said well my next truck won't be sold by you for sure.

 

[Ltngdrvr]

My diesel truck used 5 gallons of DEF in 4207 miles which I think is way too much, I went to my dealer again which I new was waste of time, his answer that's on the high side but close to normal for your truck because you tow a boat use will use more. I said that is bull stored, I quietly look at dealer said well my next truck won't be sold by you for sure.

Mine uses way more DEF than that when towing.
If you got that kind of DEF mileage while towing the boat, your truck is doing just fine, dealer was right about that.

 

[AH64ID]

My diesel truck used 5 gallons of DEF in 4207 miles which I think is way too much,

Thought I had replied earlier...

That would be 841 mpg DEF, and my lifetime average is 883 with a 30% towing and an overall diesel mpg of 12.9. I get about ~500 mpg towing and ~1000 mpg empty on DEF.

 

[NIsaacs]

Another update again....for those that may actually care
284,827 miles
691.592 gallons
$1,975.99 dollars
411.84 avg mpg of DEF
$2.857 average cost per gallon
$0.0069375 cost per mile
$6.94 per 1,000 miles
27,627.4 gallons and $69,290.66 of #2 has been consumed....and the DEF rate is 2.5032%. Lifetime #2 mpg is 10.28 mpg.
All of the above DEF was purchased bulk at the pump.

Couple of fill-ups combined here.

Miles: 6350
Hours: 174
Gallons of DEF: 6.876
MPG DEF: 923
Average DEF GPH: 0.039
Gallons of Diesel: 478
MPG Diesel: 13.3
Average Diesel GPH: 2.75
% DEF:Fuel: 1.4%
Towing miles: 1921/30%

Brings my life average to 883 mpg, 0.042 GPH, and 1.62% DEF:Fuel. Lifetime 12.91 mpg diesel.

Big difference between Greg and John here. I don't think I am all that far off from Greg.

When I picked up my truck I asked what the crystal like substance was below the fuel door, the truck prep guy said they overfilled the def tank. So if my tank was full (the gauge said it was) and I drove it 1623 miles to 1/4 tank, that is about 360 miles per gallon using the gauge. Is my gauge that far off? I don't think so, it is a new truck, why would it be The fuel gauge seems close. I dumped in a jug and the gauge went back up to almost 3/4, I hauled another 186 miles and it went down to 5/8's tank.

The gauge went down slow for the first 900 miles, running empty. The second 900 miles, towing, I could watch it go down.

I think you guys are beating me up for no reason

 

[AH64ID]

Big difference between Greg and John here. I don't think I am all that far off from Greg.

When I picked up my truck I asked what the crystal like substance was below the fuel door, the truck prep guy said they overfilled the def tank. So if my tank was full (the gauge said it was) and I drove it 1623 miles to 1/4 tank, that is about 360 miles per gallon using the gauge. Is my gauge that far off? I don't think so, it is a new truck, why would it be The fuel gauge seems close. I dumped in a jug and the gauge went back up to almost 3/4, I hauled another 186 miles and it went down to 5/8's tank.

The gauge went down slow for the first 900 miles, running empty. The second 900 miles, towing, I could watch it go down.

I think you guys are beating me up for no reason

Yep, Greg uses about 56% more DEF than I do. 2.5% to my 1.6%, for only a 20% lower lifetime mpg.

The gauges are not float gauges like a fuel tank, so they don't move or react quite the same. That's why sometimes it will seems to move slow and others it will seem to move fast. It takes a couple gallons to even come off of 100%, so if you saw it moving the first 900 miles empty I would *guess* it wasn't topped off.

Sub 400 mpg DEF is pretty low for these trucks, even the 19+ SO's that seem to be thirstier...likely due to the higher compression. The harder you work the motor the less the EGR works so DEF has to pick up the slack.

360 mpg DEF with 10.8 mpg diesel would be right at 3%, which is within the industry standard of 2-3% but higher than I've seen most report with this application. I have yet to see more than 2.1% average on a DEF tank but have hit 2.1% twice. Once was elk hunting and the other was a 2K mile road trip at 11.1 mpg and 80% towing. I didn't even see the gauge move for the first 1000 miles or so and then it dropped to 3/8 over the next 1000 miles.


It's just more fun to beat you and your purdy new truck up a bit

I have read lots of threads on other forums of people complaining about DEF usage and they all seem to be getting about 500 mpg DEF towing and 1000 mpg DEF empty... but still think its excessive.

 

[NIsaacs]

Okay, that helps explaining the goofy gauge. I have given up watching the gauge summary in the display, the engine coolant is all over and the transmission temp seems to stay at 168 degrees.

I did read this thread completely and it seems the def usage is from 200 mpg to 1500

 

[AH64ID]

I have given up watching the gauge summary in the display, the engine coolant is all over and the transmission temp seems to stay at 168 degrees.

Me too for the most part. I use the coolant needle as it doesn't bounce as much.

Between the EGR cooler and over a gallon less coolant in the block than a 5.9 the ECT really moves a lot, and fast. I can be on a 5 minute idle cool down after towing and the ECT is still above 200°.

 

[Ltngdrvr]

Yeah, really doubt they filled the DEF at the dealer, probably just spilled it or tried to add it too fast. Surprised they hadn't cleaned their spill up before you saw it.
DEF won't harm paint, but will corrode bare metal pretty quickly, so always best to wash spills off ASAP.

 

[gsbrockman]

Another update again....for those that may actually care
341,914 miles
851.54 gallons
$2,462.01 dollars
401.52 avg mpg of DEF
$2.891 average cost per gallon
$0.0072006 cost per mile
$7.20 per 1,000 miles
33,651.6 gallons and $84,709.21 of #2 has been consumed....and the DEF rate is 2.5304%.
Lifetime #2 mpg is 10.15 mpg.
All of the above DEF was purchased bulk at the pump.

 

[AH64ID]

My last 2 fill ups

7/30/21
Miles: 2,195
Hours: 64
Gallons of DEF: 3.680
MPG DEF: 596
Average DEF GPH: 0.0575
Gallons of Diesel: 191.3
MPG Diesel: 11.47
Average Diesel GPH: 2.99
% DEF:Fuel: 1.9%
Towing miles: 1249/57%

10/7/21
Miles: 4,994
Hours: 121
Gallons of DEF: 4.774
MPG DEF: 1046
Average DEF GPH: 0.039
Gallons of Diesel: 291.43
MPG Diesel: 17
Average Diesel GPH: 2.41
% DEF:Fuel: 1.6%
Towing miles: 783/16%


Brings my life average to 887 mpg, 0.043 GPH, and 1.64% DEF:Fuel. Lifetime 12.90 mpg diesel.

 

[Wiredawg]

My last 2 fill ups

7/30/21
Miles: 2,195
Hours: 64
Gallons of DEF: 3.680
MPG DEF: 596
Average DEF GPH: 0.0575
Gallons of Diesel: 191.3
MPG Diesel: 11.47
Average Diesel GPH: 2.99
% DEF:Fuel: 1.9%
Towing miles: 1249/57%

10/7/21
Miles: 4,994
Hours: 121
Gallons of DEF: 4.774
MPG DEF: 1046
Average DEF GPH: 0.039
Gallons of Diesel: 291.43
MPG Diesel: 17
Average Diesel GPH: 2.41
% DEF:Fuel: 1.6%
Towing miles: 783/16%


Brings my life average to 887 mpg, 0.043 GPH, and 1.64% DEF:Fuel. Lifetime 12.90 mpg diesel.

Your numbers makes me feel pretty good about mine... 10.6 MPG almost driving it like I stole it. With not pulling anything and a 9 gallon DEF tank, I'm coming up on 2.5 gal add mark and can calculate the DEF MPG. I LOVE THIS TRUCK! Nothing like quiet, massive power without smoke. Same on the 09 4500 running Smarty on level 5. Rocks!

Thanks, Ron

 

[NIsaacs]

Using the jug method, (John and Greg)

I am at 450 mpg, 9k and 20 gallons.

 

[AH64ID]

My last 2 fill ups, and likely the last ones I'll do in this truck. I'm curious to see how the '22 will compare.

12/15/21 - Post Elk Hunting, lots of slow miles.
Miles: 2,382
Hours: 103
Average MPH: 23
Gallons of DEF: 3.785
MPG DEF: 629
Average DEF GPH: 0.037
Gallons of Diesel: 287.4
MPG Diesel: 8.3
Average Diesel GPH: 2.79
% DEF:Fuel: 1.3%
Towing miles: 1006/42%

6/4/21
Miles: 5,408
Hours: 137
Average MPH: 39
Gallons of DEF: 4.869
MPG DEF: 1111
Average DEF GPH: 0.036
Gallons of Diesel: 390.8
MPG Diesel: 13.8
Average Diesel GPH: 2.85
% DEF:Fuel: 1.2%
Towing miles: 572/10.5%

This was my best mileage yet, and 4th fill up over 1000 mpg.


Brings my life average to 880 mpg, 0.041 GPH, and 1.57% DEF:Fuel. Lifetime 12.95 mpg diesel.

 

[Turbo Terry]

4000 miles to 4 gallons

 

[Turbo Terry]

John so you have ordered a new truck then?

 

[C M McCormick]

625 miles per 1 gal of DEF. I have little over 16,000 miles on the truck now with around 4,000 tow miles. 5th wheel loaded weight 10,000lb.

Craig

 

[AH64ID]

John so you have ordered a new truck then?

Yes, I ordered one on xmas eve.

 

[Wiredawg]

John left a little clue... He has pic of what he ordered in his avatar.

 

[Turbo Terry]

Nice. Should be getting it soon then ho 6 speed I presume. You will like it I .think

 

[josephc1]

Hard to tell. With what was the pandemic and now the price of diesel the truck is mostly a garage queen.