DEF Newbie Question - Gauge Level and Refill

[Newsa]

It's really hard to gauge, with any kind of accuracy, DEF consumption, by re-filling 2.5 gallons at a time. If you're pulling a 4-car trailer, that in itself would limit the fuel retailers where you could buy fuel. I'd thought you would be buying bulk at the pump......due to DEF cost savings as well as the ease of negotiating your truck & trailer for fuel purchases.

DEF consumption is easily calculated by filling it all the way up, then re-filling at the pump, with total gallons used (just like hand-calculating fuel economy)

600/2.5= 240 MPG of DEF......that's definitely on the low side.

I would agree. * And add that the highly inaccurate gauge adds to the complication of knowing def use/consumption*

 

[Mingoglia]

Yeah, the gauge is funny. When mine was full I never thought the damn thing would ever move. I was driving around for hundreds of miles. Then all of a sudden it moved and from that point you can practically watch it move. Then it slows down again around half, then speeds up again.

 

[zzollwalk]

I buy 2 jugs of def (2.5gals) from Advanced Auto for $9.99 per jug..I usually get a $5.00 coupon to go with that..I don't buy it at the truck stop although I probably could..I think it's cheaper the way I get it..

 

[Cummins12V98]

I easily fit a 2.5 in at 1/2 tank. Big question is how old is this "FREE" DEF? Just fill up at the truck stops it's cheap and easy.

 

[zzollwalk]

So now my question is does anybody know what happens if you use old def?? Also do the jugs have an expiration date on them?? Even if it is on the shelf, how old could it possibly be?? Just saying..

 

[Newsa]

So now my question is does anybody know what happens if you use old def?? Also do the jugs have an expiration date on them?? Even if it is on the shelf, how old could it possibly be?? Just saying..

It typically goes on sale at advance auto if its been in the store for 10-14 months. According to date code (Peak).

At advance auto this past january, i felt lucky to get a 2 month old carton..... all the other cartons were 5-6 months old. *I think the other fresh stuff was in the back.

 

[kthaxton]

and here I am......not dwelling on DEF. :-laf

 

[Newsa]

I easily fit a 2.5 in at 1/2 tank. Big question is how old is this "FREE" DEF? Just fill up at the truck stops it's cheap and easy.

If it sits in the trucks tank in hot weather, the water (solvent) can evaporate quicker than the potency of the def diminishes. *But this will not likely be a concern if you drive more than 15,000 miles per year. * If the def becomes too concentrated, it can crystallize in your def nozzle or def pump. *These are the non-warranty claims you occasionally hear about. *If DEF sits in the store too long, the urea can (slowly) react with the water that it is dissolved in causing the def to become a weaker solution of urea. * This won't harm your truck. * Your truck will just adjust and pump a bit more def into the exhaust stream *(up to a point). * *If you get a low def quality message, you can still drive it. *But if the message bothers you, drain the def tank. *And refill.
Running weak def, you can also get a p2201 DTC. *I cleared mine, and it hasn't come back.

 

[rashwor]

If it sits in the trucks tank in hot weather, the water (solvent) can evaporate quicker than the potency of the def diminishes. *But this will not likely be a concern if you drive more than 15,000 miles per year. * If the def becomes too concentrated, it can crystallize in your def nozzle or def pump. *These are the non-warranty claims you occasionally hear about. *If DEF sits in the store too long, the urea can (slowly) react with the water that it is dissolved in causing the def to become a weaker solution of urea. * This won't harm your truck. * Your truck will just adjust and pump a bit more def into the exhaust stream *(up to a point). * *If you get a low def quality message, you can still drive it. *But if the message bothers you, drain the def tank. *And refill.
Running weak def, you can also get a p2201 DTC. *I cleared mine, and it hasn't come back.

So in other words, you folks need to spend more time actually driving these beauties than sitting on the porch staring at them. Sorry, I could not resist! All in fun; no offence meant. I put 30 to 36k on mine a year and tow regularly, so if I can ever afford to move up, it probably won't be a issue for me.

Congrats on the new ride Rusty.

 

[Newsa]

So in other words, you folks need to spend more time actually driving these beauties than sitting on the porch staring at them. Sorry, I could not resist! All in fun; no offence meant. I put 30 to 36k on mine a year and tow regularly, so if I can ever afford to move up, it probably won't be a issue for me.

Congrats on the new ride Rusty.

My dog gets her best snoozes on the back seat when its not too hot out and I have no place to go.

 

[Kirwin]

Just as a case in point I pull a 12K trailer about 75% of the time and I get around 800MPG DEF.

 

[qwer010203]

Thanks for the information there mate!

 

[josephc1]

I bought a new to me 2014 2500 6.7 with 26K on the clock in May of this year, the DEF gauge read full. I have since put about 700 miles on the truck and the DEF gauge still reads full. I have pulled my 10K pound 5er twice for short 100 mi trips, I was starting to think the gauge was stuck till I read the above post. I'll take the advise here and run it low till I get the warning and from there only ad a jug at at a time unless I'm going on an extended trip. My thanks to everyone for there insight and advise.

 

[RustyJC]

As far as the age of the free def, as closely as I can translate the Peak date code, it was packaged in April 2016. At a gauge reading of just below 1/2 tank, I got a 2.5 gallon jug in which brought the gauge to full.

Rusty*

 

[SMcGrady]

My dog gets her best snoozes on the back seat when its not too hot out and I have no place to go.

If the door is open, my chocolate lab will be up in the truck snoozing too. Lol

 

[Newsa]

I bought a new to me 2014 2500 6.7 with 26K on the clock in May of this year, the DEF gauge read full. I have since put about 700 miles on the truck and the DEF gauge still reads full. I have pulled my 10K pound 5er twice for short 100 mi trips, I was starting to think the gauge was stuck till I read the above post. I'll take the advise here and run it low till I get the warning and from there only ad a jug at at a time unless I'm going on an extended trip. My thanks to everyone for there insight and advise.

I have actually never got as far as getting the warning messages. The reason for that is I always get a P20ee CEL/MIL when I get down to what the gauge tells me is 1/4 full (but I suspect it's closer to 1/8 full).

When I add a gallon or more of DEF, the CEL/MIL goes away.

The truck has trained me not to let it get too low on DEF

 

[Bob4x4]

I have actually never got as far as getting the warning messages. The reason for that is I always get a P20ee CEL/MIL when I get down to what the gauge tells me is 1/4 full (but I suspect it's closer to 1/8 full).

When I add a gallon or more of DEF, the CEL/MIL goes away.

The truck has trained me not to let it get too low on DEF

Actually your cel is telling you to fix it........

 

[Newsa]

Actually your cel is telling you to fix it........

Yeah. I was just telling the TDR member there might be a CEL long before the 200 mile warning