Def usage?

redwngr · November 17, 2020

On 5/27/2020 at 7:40 PM, MTU Alum said:

The emissions requirements have tightened since 2017 so will have to use more def to be compliant.

#iworkforGM

What % of fuel should be expected now?

Back in 2010/11 when DEF was new there was a GM document that indicated about 1.5% of fuel, iirc.

(so 1.5 gal def per 100 gal fuel)

Is there an updated document / number available?

Njmurvin · November 17, 2020

My truck has about 1400 miles on it - probably half of that towing my 12K lb fifth wheel. On one of my visits to the service department for an oil leak, they re-flashed my computer which was supposed to make the DEF gauge more accurate. I am currently showing about 1/2 tank on the DEF gauge.

07HD · November 20, 2020

Just had my 2020 in for my free oil change at 1100 miles, They said there was a recall I guess he meant service bulletin. They installed a new program for the Def system and filled the tank up. My gage wasn't going down very quick, it even went back one bar before I took it in and I've never added any fluid. Guess will see how it works now.

shadow gray 2020 hd · November 27, 2020

After about 1000 miles, the def gauge on my truck finally came down off full. Another 500 miles it has dropped another bar. Will let it get down to 3 bars and see how much it takes to fill it back up. But appears the gauge is working.