How Much DEF Are You Using In Miles?

[gsbrockman]

Decided I’d update this thread with some up to date information.....

Through 68,722 miles, White Lightning has consumed 144.301 gallons and $405.93 dollars of DEF.

This equates to

• 476.24 average mpg
• $2.813 average cost per gallon
• $0.0059068 per mile
• $5.91 per 1,000 miles (much easier to comprehend)

 

[Jrsweet16]

Mine uses bout 1/2 a tank every 1900-2100 miles, what is half tank a little more than 2.5 gallons, but trucks runs empty no towing......


Yetttttttt

 

[Wiredawg]

All good info. Prior to purchasing my truck, I had zero understanding how DEF works. Completely counterintuitive based on how my previous non DEF 09 4500 worked... the heavier the duty cycle, it had fewer regens because the temp of exhaust gasses heated DPF where particulate burned off. On DEF trucks, the higher the duty cycle, the higher the DEF use.

There's a great article TDR sent out about it that shows DEF system components can be cleaned with water and restored to service. Definitely worth reading.

Cheers, Ron

 

[kthaxton]

Completely counterintuitive based on how my previous non DEF 09 4500 worked... the heavier the duty cycle, it had fewer regens because the temp of exhaust gasses heated DPF where particulate burned off.

That is still the case on new trucks...less regens when worked hard, in fact there are fewer regens even when not towing on current trucks.

On DEF trucks, the higher the duty cycle, the higher the DEF use.

That is because DEF use is directly tied to fuel consumption. Use more fuel (towing), use more DEF. Keep in mind, DEF has nothing to do with regen.

 

[Wiredawg]

Hey kthaxton, sooo, is regen still initiated with increased fueling on the front end when there is reduced pressure measured at the second air pressure sensor on the DPF? Is DEF also injected into the DPF and is it just to eliminate NOX? This is the first diesel truck I haven't installed an EGT gauge, so have no idea when regen occurs. The only way I could tell on my 09 4500 was higher EGTs and higher RPMs when idling. I appreciate the patience in getting me through this. Ron

 

[Wiredawg]

kthaxton, I just read part of my OEM service manual on exhaust system and DEF. It's nice to finally understand my truck and how it functions. Nothing like an education after the fact. Thanks, Ron

 

[Cummins12V98]

At 24k I was 505mpg with 10k of that towing.

 

[RMADSEN]

I have a 2012 4500 c/c crew with the Aisin trans that carries a 3500 lb Lance camper + other camping gear. The truck has 52K miles. I fill DEF from bulk at truck stops. I have gotten 700 to 900 miles to the gallon of DEF ( never less than 700 miles per gallon).

 

[Cummins12V98]

Towing my combined is 33-35k.

 

[AH64ID]

Bringing this one back to life.

I did my first full fill-up of DEF since the dealer topped it off in March. I'm just trusting they filled it with a pump and it was full, if they just used jugs my usage was even lower.

7,844 miles
9.058 gallons of DEF
865.9 mpg/DEF
569 gallons of diesel
1.6% DEF to Fuel
13.7 avg mpg (low of 9.1, high of 20.1)
2200 miles towing, generally ~18-20K GCW.

I had thought DEF usage would be higher, but I'm not going to complain.

 

[Dan_69GTX]

This summer going to AZ, with empty trailer, 7w x 16l x 7.5'high and pushing it ( I didn't care about mileage - I wanted to get there fast), got 10.2MPG and 660 MPG def.

Coming back to VA, about 5k load in trailer and 1K in truck (total guess on weight -based it upon how it pulled) - more leisurely drive, 11.9MPG and 540MPG def

 

[JET]

I have a 2014 that I bought new. It now has 96000 miles on it, mostly in town and periodically pulling a 28 foot Forest River travel trailer and I am getting 1426.5 miles per gallon of DEF.

 

[AH64ID]

mpg on DEF is quite subjective without average fuel economy too.

If possible folks should post both numbers, or a use rate as well, since the DEF burned has a direct correlation to fuel burned.

I have a 2014 that I bought new. It now has 96000 miles on it, mostly in town and periodically pulling a 28 foot Forest River travel trailer and I am getting 1426.5 miles per gallon of DEF.

You get some good average mileage, thou your photo looks like a 2wd?

Based on what you've posted that would be about 67 gallons of DEF in 96,000 miles.
At 1% dose rate that would be about 14mpg
At 2% dose rate that would be about 28mpg
At 3% dose rate that would be about 43mpg

I'm going to go out on a limb and guess your're not getting better than a 25 mpg average.

So, that begs the question is 2-3% really the correct average?

 

[TCDiesel]

I have a 2014 that I bought new. It now has 96000 miles on it, mostly in town and periodically pulling a 28 foot Forest River travel trailer and I am getting 1426.5 miles per gallon of DEF.

That's amazing MPG/DEF. Your using 1 OZ of DEF Per 11.1 miles. AVG. With Pulling is unheard of.

 

[Newsa]

That's amazing MPG/DEF. Your using 1OZ of DEF Per 11.1 miles. AVG. With Pulling is unheard of.

Actually, it is more like 0.996 oz per 11.1 miles.

That is close to 1/3 of what GSBrockman is using in his post above.

 

[TCDiesel]

[-p';;;;;

Actually, it is more like 0.996 oz per 11.1 miles.

That is close to 1/3 of what GSBrockman is using in his post above.

My math stills were only off -0.004, thanks for the correction.

 

[Newsa]

[-p';;;;;


My math stills were only off -0.004, thanks for the correction.

I thought they were off by a factor of 10. You said 10 oz/11.1 mi????

 

[AH64ID]

I thought they were off by a factor of 10. You said 10 oz/11.1 mi????

haha.

1OZ vs 10OZ

More coffee before reading numbers

 

[TCDiesel]

Ha Hu AD, Newsa a Math Teacher, he needs to set a good example for His Students.

 

[Newsa]

Ah. I see my mistake. But if you do the same math with gsbrockman's numbers..... His is close to 3 oz per 11.1 mile. So it is not an unreasonable amount of def.