DEF usage?

[Major Malfunction]

96k on my 2018. Previously I was blowing through DEF while still under warranty about 40k miles ago and had an injector replaced. Been normal since then. Had a camping trip this weekend with my 10k 5th wheel. Was at half when I left. Put in 2.5 gallon jug. Did about 500 miles and now down to less than 2/3. No codes or anything abnormal and she pulled like a beast with normal mileage, etc. Either the gauge is flakey or I'm using way too much DEF.

Did not do 67A recall yet but at this point I'm thinking I should do i can get under the 4 year warranty in case it is the injector, etc.

What's the brain trust here think might be happening and is going for the 67A my best strategy? I say that in case it's the injectors and I don't have to pay out of pocket with the coverage?

 

[Diesel85]

I would pull the DEF injector and clean it with a Bissell Steam Shot or equivalent.

Also temperatures and humidity make a huge difference on DEF usage to reduce NOx.

I noticed both my work 2020 Cummins 3500 and my 2020 EcoD used a lot more DEF this year than last only because it's been hotter up in the North East.

 

[Grumpy8811]

DEF usage is tied to the amount of load and speed driven it is worth saying different programming for different years changes the amounts as they can use both EGR and SCR for NOx control, if they currently program to use more DEf and less EGR, you just drink more DEf.

back in the day when Cummins first started going with selective Catalytic Reduction, the training literature implied 50 gallons of Diesel to 1 gallon of DEF is about normal usage under load.. ten miles per gallon pulling a trailer would equal 1 gallon of DEF per 500 miles..

 

[reveldark]

Hey mate, definitely get that recall done while you can mate.

 

[AH64ID]

It’s hard to use just the gauge to determine DEF usage since the gauges aren’t liner nor do they use a float.

~500mpg towing is why I got with my 2018.

Get 67A done, and be happy if your DEF consumption goes up since that means less EGR.

My 2022 gets ~350mg towing but uses a lot less EGR. The EGR crossover tube isn’t discolored yet at 24K miles and and it was discolored by 5K miles on the 2018.

 

[Turbo Terry]

I had mine done. Sticker under the hood