2014 Ram 1500 Ecodiesel: DEF Jam IV
January 6, 2015
The DEF gauge on our 2014 Ram 1500 Ecodiesel sank into the red zone as I towed Josh's racecar southward towards home. I know what you're thinking: "Didn't they add DEF just a few weeks ago?"
Well yes, and no. Yes, we last filled the tank on October 25. And, yes, the day I added it was November 30.
But you must remember this: We put over 5,000 miles on our Ram in November alone. That's anywhere from three to five months for most people. We had driven 5,335 miles since our last DEF add, and a good percentage of those were towing miles.
Also, the DEF tank wasn't quite empty when I added my 6 gallons. The warning lights had not yet come on. I could have stretched it out another 500 miles or more. But the needle was clearly in the red, and I don't like handing over a vehicle with an impending issue to the next guy or gal.
Besides, I'd never yet added DEF to any vehicle. I was curious.
So I bought two 2.5-gallon containers at my local auto parts store. I might have considered buying a third if they'd had one, but a part of me thought the tank wasn't empty enough for 7.5 gallons. Also, the manual is pretty adamant about not overfilling. So I bought a single gallon instead, even though the smaller container carried a much higher per-ounce price. Ketchup and DEF have that in common.
In all I paid $40.47 for 6 gallons, which works out to $6.75 per each. Our Ram's DEF consumption rate over 5,335 miles was 890 mpg and the per-mile cost of the stuff boils down to three-quarters of a penny.
The 2.5-gallon jugs came in their own cardboard boxes, each containing a screw-on spout. The spout was pretty effective, and it screwed on to the 1-gallon container just the same, which was good because the smaller jug didn't come with one.
It turns out that 2.5 gallons is just about the right size for a jug of this stuff. A decent amount goes in during a single pour and it doesn't weigh enough to be unwieldy.
My six-gallons came up just shy of full, but I don't think 7.5 gallons would have fit without spilling. If I had it to do all over again I'd wait until the needle sank a little lower and the warnings came on, at which point 7.5 gallons would be almost exactly right.
I think I'd approach this differently if I owned this truck and wasn't sharing it with others. For one, I'd only be putting on 1,200 miles a month. At my usual mileage accumulation rate I figure I'd be adding three such jugs every 4 or 5 months, which seems very easy to manage. Or maybe I'd add a single 2.5-gallon jug every month or two and be happy keeping the needle somewhere in the middle. I'd probably make sure I always had an extra 2.5-gallon jug on the shelf at home, too.
And I'd buy my DEF online from an Amazon vendor, where the going rate is $11.97 for a 2.5-gallon container of the exact brand I bought. That works out to $4.79 per gallon and only a half-cent per mile.
Either way, this DEF thing isn't that big of a deal. It's pretty easy to manage, and it's easy enough to add that I would never consider paying the dealer to do it for me.
Dan Edmunds, Director of Vehicle Testing @ 21,083 miles