First time towing in the 3.0 Duramax - DEF usage?

DemonWorks · October 3, 2020

Hey guys, i'm going to be towing (open trailer with Camaro - maybe 6000 lbs) in about 2 weeks for the first time in this truck - 2020 Silverado 3.0L Duramax - It's roughly 1500 miles total with hills (Utah to California and Back)

My question is, knowing the DEF usage is engine load dependent, what kind of usage should I expect?

I don't want to buy DEF while i'm out, I have my own I can bring with me if needed. I have 800 miles on the truck and the DEF gauge has not changed at all but I have also not towed or put it under any extreme load.

I'm anxious for this trip because I just did this same trip in the 5.3 nearly identical truck and I get to see how to the two compare in terms of towing and mileage.

If you don't follow the YouTube channel - please do as I will make a full video on the first time towing with this truck.

Thanks

Edited October 3, 2020 by Carbon

CamGTP · October 3, 2020

If you ask me there are too many variables. Where you live, the weight, your driving style, how fast/slow you are going to drive. It's going about double the DEF usage while towing if you ask me.

Fill the tank full before you leave and fill it when you get back home. Then you'll have a real number that your truck uses.

DemonWorks · October 3, 2020

Yeah, i'm more after if the tank will be sufficient and I can leave any extra at home. I saw someone post some crazy amount of usage when towing but that's the only post I found.

yousaveone · October 4, 2020

It uses 3 times more when towing. My truck get 30mpg not towing and uses 1 gallon per 1K. When towing its easily 3 gallons per if not more. Your mileage will also drop significantly. Expect 15MPG. I have 30K on my truck with 5K towing so my numbers are pretty solid. When I tow I bring 4 2.5 gallon boxes.

I hate the 5 gallon buckets. Tractor supply has 2.5 boxes for $7 as does walmart. As long as it says API on the box its good; and they all are API certed.

BurnsMax · October 4, 2020

I would bring a 2.5 gallon jug to be safe. It will start guzzling DEF with that weight.

redvettez06 · October 4, 2020

Which YouTube channel?

redwngr · October 5, 2020

Fill the def tank so you can do a hand calculated calculation of what it uses.

Despite what the range/level def indicator may say, it is common for def tanks not to get filled before delivery. The only way to know it was full, so you an accurately check usage, is to top it up and record the odometer reading -- and later repeat.

Def usage should be in direct ratio to the amount of fuel used. (somewhere around 2 gal def per 100 gallons of fuel)

If change in vehicle usage results in twice as much fuel being used, it will also use twice as much def.

Def is available everywhere that diesel is available. (if a station is really low diesel volume and doesn't have def, then it's not a place that I would be buying diesel)

If it starts giving def level warnings get some def at the next fuel stop.

Jgreene11 · October 5, 2020

Just towed 500 miles each way, towed 5000 lbs and my truck guzzled DEF. I would bring some for sure.

DemonWorks · October 5, 2020

Thanks everyone ! That's what I was looking for !

DemonWorks · October 5, 2020

20 hours ago, redvettez06 said:

Which YouTube channel?

www.youtube.com/TrashPandaProductions

aseibel · October 5, 2020

The weight of your trailer is only half of the equation. A camaro on a flatbed is relatively easy to pull through the wind on the freeway compared to a travel trailer or cargo trailer of the same weight. You have much less wind drag, I wouldn't expect your truck to need to work that hard. But please post your results so we have some actual data.

Duramax3oh · October 7, 2020

I don't seem to use much DEF until I tow, then it gulps the stuff. You WILL need to add more during your trip so if I were you I would take one or two of the 2.5 gal boxes with you to be safe. Also, do not pay attention to the DIC DEF gauge as it does not reflect accurate levels... at least mine doesn't. At all... You will get alerts indicating how many miles you have left for DEF (ex: 980 miles, 300 miles, etc)... that's what you should really pay attention to.

Also a word of advice that has come in handy several times for me already. Keep the little funnel/nozzle deal that comes with the 2.5 gal blue def box. Some stations that don't have DEF by the pump may sell the jugs of DEF. More often than not they're the smaller jugs that don't have the funnel nozzle so you're kinda screwed if you don't have another solution

Grover67 · October 7, 2020

Have any of you have the DEF service bulletin update done or not? Worse usage before or after it?

-Grover67

Duramax3oh · October 8, 2020

On 10/6/2020 at 7:38 PM, Grover67 said:

Have any of you have the DEF service bulletin update done or not? Worse usage before or after it?

-Grover67

Yes I believe that was one I went in for. I haven't noticed a difference but I didn't really have a good baseline to judge that from. All my towing has been after the update.

DemonWorks · October 21, 2020

I ended up using just over 3.5 gallons on my 1300ish mile trip towing. I added 2.5 when my display told me I had 300 miles remaining and it still showed 1/2 tank. when I got home i topped off with just over 1 gallon bringing the total to just over 3.5 gallons.