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I'm averaging about a gallon for every 1100 miles I drive. So many variables effect DEF use. I noticed it does burn more when I am towing. Top it off yourself, drive 2500 miles and see if it will take another 2.5 jug.
 

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DEF Usage

I'm averaging about a gallon for every 1100 miles I drive. So many variables effect DEF use. I noticed it does burn more when I am towing. Top it off yourself, drive 2500 miles and see if it will take another 2.5 jug.
I topped it off with a full 7 gallons, at just over 1500 miles my "Action Required" notification came on said 500 miles left. I added 5 gallons, at just over 1200 miles, the same notification came on. I have just over 14000 miles on my 2019 Denali Duramax 2500 now so I'm thinking I have a real problem but GM is saying normal usage. Is there anything I can do?
 

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I'm averaging about a gallon for every 1100 miles I drive. So many variables effect DEF use. I noticed it does burn more when I am towing. Top it off yourself, drive 2500 miles and see if it will take another 2.5 jug.
I topped it off with a full 7 gallons, at just over 1500 miles my "Action Required" notification came on said 500 miles left. I added 5 gallons, at just over 1200 miles, the same notification came on. I have just over 14000 miles on my 2019 Denali Duramax 2500 now so I'm thinking I have a real problem but GM is saying normal usage. Is there anything I can do?
Is your def usage more than 2% of fuel usage?
 

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Yes, it's more like 3 to 3.5%.
Am I reading this right?

You get 1200 mile on 5 gallons of def?

Which implies 1200/5 = 240 mpg (of def)

and that's 3.5% of fuel

so 240 x 0.035 = 8.4 mpg of fuel.

(Then to check 1200 miles/8.4 mpg -- 143 gallons of fuel
and 5 def / 143 fuel x 100% = 3.5%)
 

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Found your forum, time to vent about DEF use. I'm at 18,000 miles in a 2019 Silverado 3500HD dually. Ran load at 12 mpg. Ran unladen at 18 mpg. Speed 70 mph. 268 mpg of DEF.

I drove 5300 miles on a round trip to Kentucky (empty-no trailer), picked up my new gooseneck, up to Illinois(empty), picked up payload (trailer/load 15000 lbs), drove through Iowa and back to California. In 5100 of those miles I used 19 gallons of DEF.

Dealer said they want to monitor my DEF use over the next month while driving around town and so called fishing trips. I told them I didn't buy a dually for use as a grocery getter. And by the way, they wouldn't rotate my tires for my first visit to them. Already performed two oil changes elsewhere prior to dealer visit.

I'm about ready for yellow side boards on my bed with some verbiage. Really like my truck otherwise.
 

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After a week in the shop, my local dealer hasn't done anything about my excessive DEF usage, says GM hasn't issued a reprogram fix for it yet. In the Owners Manual, it says you should get "several thousand miles" on a tank of DEF, my tank is 7 gallons. It also says there should be 3 notifications; mine goes straight to "Action Required, add DEF now". Also, it seems to me if so much DEF is injected into the system, it has to be damaging other parts. And I know my fuel mileage has decreased since the DEF usage has increased. It's time for everyone who has this issue to call GM Customer Relations at 800-222-1020 and voice your concerns and disappointment about their reluctance in getting this problem resolved. It seems they did a recall for the 2017-2018 Duramax models but aren't extending it to the 2019 models yet.
 

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The person you were talking to is full of of crap.

Programming won't be different on 20% of them.....


(if there was a programming change, then it would be vehicles before a certain build date (or serial number) not a random 20%)
Not so, it seems to be a random number of trucks--I've talked to owners of 2019 trucks who go service to service (7000+ miles) before adding DEF, and others who are using like mine, 1500-2000 miles per 7 gallon tank.
 

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Anyone consider reporting this problem to EPA? Hey, figured we could all use some levity... the Gov, “helping”...
 
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