DEF Usage

fish

Polish Mafia
Staff member
Jul 26, 2012
110
7
18
Peoria, AZ
I’ve been towing with my 2019 Silverado 2500 pretty much steady for the last 1,000 miles. I’ve only towed the toyhauler with a side by sides loaded up I’m right around 14k lbs.

The last time I filled up with DEF was also 1k miles ago, today I plugged in my ODB2 scanner just to double check before the next trip and I noticed the DEF tank is down to 38%. Not sure how accurate that is, but I’ll be heading to the truck stop to fill up tonight.

What are you guys seeing for your DEF usage?
 

KyleC4

Tech
Dec 30, 2016
470
48
28
Bay Area
So the wife’s ‘19 3500 Denali dually would use quite a bit at first when new. Hauled a 3 horse living quarters trailer to SoCal empty @ 12k lbs. Then came back with one horse so weight only a little over 13k. Roughly 1600 miles trip she went through 5 gal of DEF. after about 5-6k on odometer though it seemed to improve. I’d say probably 1k miles per gallon. But she hauls the horses a lot.
 

fish

Polish Mafia
Staff member
Jul 26, 2012
110
7
18
Peoria, AZ
So the wife’s ‘19 3500 Denali dually would use quite a bit at first when new. Hauled a 3 horse living quarters trailer to SoCal empty @ 12k lbs. Then came back with one horse so weight only a little over 13k. Roughly 1600 miles trip she went through 5 gal of DEF. after about 5-6k on odometer though it seemed to improve. I’d say probably 1k miles per gallon. But she hauls the horses a lot.

Got it, thanks for the input.

Turns out my tank level was off. Way off. Stopped by the truck stop was only able to fit 2.25 gallons of DEF. Usually when I'm down to 25% i'm able to fit 5.5 gallons.

Definitely using DEF quicker while I'm towing, but no that drastically. If my math is right, and it's probably wrong, I could probably go 2,000-2,500 miles while I'm towing. Time will tell.