DEF

How big are the DEF tanks?

My 2013 tells me the level is "O.K." First alert was remaining miles is (approximately) 980 miles. After a 150 miles pull, it showed me a 27 % level. I added the 2 1/2 gallon container I had and indicator told me the DEF level was O.K. I then added another 2 1/2 gallon 2 days level. I have about 5900 miles with about 1500 miles towing. Have not found any indication that I can see level or remaining miles when I scroll through the DIC. Still new to me and I have no idea how much GM put in the tank but based on the reading I first received, it appears to be based on 2 1/2 gallon levels. Will have to wait and see what I get after being close to a full tank.

No big deal, have only "messed" with it for 2,000 miles, added two gallons because it wasn't full when I got the truck on May 9th. Have a gage, I'll use it, plus you have warnings if and when you need them. I purchased 2.5 gallon Blue DEF for $11, "just in case"...carry it in truck tool box...Only time I added was at truck stop for $2.89, and again, two gallons filled it to the top.....don't know how much was in there to begin with, but it wasn't full.

Cheapest is to find a place that has it at filling station and add DEF there...Have a place about 5 miles down the road, diesel pump and right beside of it is a DEF pump...

As stated above, better mpg with DEF equipped vehicle..I owned a 10' and 12' Ram dually, same configuration as 13' in my sig. and I'm getting 2 mpg more with the DEF equipped 13' than the other two...

I added the cost up a while back. IIRC it was about 2/10 of a cent per mile. The added cost is easily outweighed by the increase in fuel mileage provided by the DEF.

My truck doesn't have a gauge,but I think all the 2012+ Duramaxes have a sensor that displays the DEF level in the Driver information center ( DIC)

It's no big deal. I just carry a 2.5 gal bottle in the truck bed. You'll get a warning when you are low, a 500 mile warning. Just pour in the battle that you have and buy another when you get the chance. Walmart is carrying it for $11/2.5 gal. So it's $11 or less if you live near a truck stop that carries it per 3000-5000 miles or so. A minor cost.

BK

Its not a problem, and I guess I live in a cold climate.

Some of the newest models now have a gauge showing how much DEF is left. Its not an issue replacing it. Widely available, I usually do the Wally World route and buy it there. Five minutes of work (or less) to refill, and frequency depends on how much you tow heavy and how you drive the vehicle. For my 2011, I suppose every 5000 miles or so I dump some in.

As before, no gauge on my 2011. But there is a place to see if it is below 1/2 tank full within the information center on my dash. So I check there every once in a while, and if below 1/2, I run by Wally World and get more.

Seems to be working fine despite the additional cost people are generally happy with the system. Dont expect any better fuel economy though. So far the milage reports I am seeing are no better and sometimes worse than my DPF equipped Cummins.

The DEF is not a big problem. The only PITA is that they don't have a gauge so that you know how much is in there. It just complains when you are about to run out.

I think it would be a pita. Especially in cold climates. That is why I have a V10 MH. JMHO.