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Has anyone experimented with using different brands of DEF to see if consumption changes? I know in past years early DEF trucks had issues using certain brands of DEF. A friend had a lot of problems with his and the dealer told him to only run AC Delco brand def in his truck. Seemed like bs but he followed there recommendation and as far as I know he never had an issue again with it. I know my ford loved to burn through Blue DEF. I would normally fill up at the local truck stop with whatever they had at the pump and my consumption was noticeably lower compared to running Blue. Unfortunately I never logged it to see what the actual difference was.
As long as the container has the ISO cert, it is DEF. To be certified as DEF it must contain 32.5% urea and 67.5% de-ionized water.
Switching brands will not matter
 

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I wouldn't be surprised if the specifications for what qualifies as urea are a little loose, which would cause some of the consumption variation people are seeing based on brand.
 

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I wouldn't be surprised if the specifications for what qualifies as urea are a little loose, which would cause some of the consumption variation people are seeing based on brand.
Actually the Automotive-grade Urea (AUS32) must meet the ISO standard 22241.
This urea contains , 0.3% Biuret maximum, 0.5 % magnesium max , 0.5 % calcium max, 0.5% phosphate max, 0.5% iron max,0.5% potassium maximum
 

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DEF does have a shelf life and that life is longer at cooler temps.

Comparing brands may actually be comparing age and or the conditions it was stored in.


Since it's usage also depends on the amount of fuel burned that also makes it tough to get a useful comparison.

Of course, YMMV :oops:
 

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I got my truck back from the dealer. They installed service bulletin N202300791. I have 1200 miles on her and now the DEF gage displays one bar has been used. So, it looks like the DEF indicator was not working and needed a software update. My truck was built in Jan of 2020. DEF is new to me. My LMM did not need DEF. If you have 1000 or more miles on your truck and the DEF indicator displays full, you may want to take it to the dealer and have it checked. The dealer balanced all 6 tires and aligned the front end. Now I can take my hand off the steering wheel and she stays in the center of the road. The steering wheel no longer vibrates at 70mph. My wife said if I turned the heated steering wheel on the vibration would give my hands a nice heated massage.
I returned to the dealer yesterday for the N202300791 service bulletin. I have 8,800 miles on my 1500 Duramax Silverado. Last week when driving from Texas to Missouri pulling a small cargo trailer, at the halfway point in the trip, the DEF warning came on that I had 1,000 miles until DEF fluid need to be added. Then just under 100 miles later, the warning came on again and said I had just 300 miles remaining until DEF would be needed. I was only about 50 miles from my destination so no big deal. Then in just 25 more miles, the warning is on again and this time says the truck will go into some limp mode soon and speed will be reduced due to low DEF. It was late and no place to stop and I made it to my location.
I added DEF the next day, about 4 gallons and things were fine. But 2 days later the 1,000 mile warning came on again, and the gauge showed full. The warning never came back on and has been fine. I explained this to the dealer and he said this was part of the service bulletin. Even though it sounded like he really didn't know if it was or not.
 

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I returned to the dealer yesterday for the N202300791 service bulletin. I have 8,800 miles on my 1500 Duramax Silverado. Last week when driving from Texas to Missouri pulling a small cargo trailer, at the halfway point in the trip, the DEF warning came on that I had 1,000 miles until DEF fluid need to be added. Then just under 100 miles later, the warning came on again and said I had just 300 miles remaining until DEF would be needed. I was only about 50 miles from my destination so no big deal. Then in just 25 more miles, the warning is on again and this time says the truck will go into some limp mode soon and speed will be reduced due to low DEF. It was late and no place to stop and I made it to my location.
I added DEF the next day, about 4 gallons and things were fine. But 2 days later the 1,000 mile warning came on again, and the gauge showed full. The warning never came back on and has been fine. I explained this to the dealer and he said this was part of the service bulletin. Even though it sounded like he really didn't know if it was or not.
This sounds like the same issue I am having with my 2020 3500HD I took it in on July 9th because it seemed like I was adding DEF all the time and getting the 1000 mile warning as well. They did some software update @ 4069 miles on the odometer. They also filled the DEF all the way up that time. Now I have been paying very close attention to it. I drove about 425(4490 on the OD) miles and it prompted for only 1000 miles left on the tank. I then filled with only 1.89 gallons of DEF Fluid at 4530 on the OD. That is only 243 miles per DEF Gallon. At 7 gallon capacity on the tank that is only 1750 miles per fill-up. That can't be normal? My 2016 LML got 4-5k between def fill-ups with a 5 gallon DEF tank. I took it back to the dealer yesterday, they have opened a case with GM and will let me know after collecting information off the computer.
 

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Can't get an official number tied down. Too many variables affect DEF usage as per some of the comments already made, e.g. frequency of regens, how hard the truck is driven, exhaust gas temperatures. My 2019 uses noticeably more DEF than the 2017, but I haven't kept an exact log so I can't post any numbers.
I am buring about 1 gal of DEF with every 1000 miles driven, is this normal? (very little towing, majority of the miles are highway miles)
 

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I am buring about 1 gal of DEF with every 1000 miles driven, is this normal? (very little towing, majority of the miles are highway miles)
Welcome to DieselPlace.
As mentioned there are a bunch of variables that affect DEF usage. ( ie. towing heavy, terrain, city vs highway driving, how you drive, etc..)
Your mileage may vary
 
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At 2850 miles I got a "DEF range 250 miles" alert message on the DIC. 100 miles later I got the "DEF low, reduced power soon" message. It took 6 gallons to fill up. Mixed city and highway, with about 600 miles towing 14,000# fiver.
 
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