I pour into a 1 gallon container.

I just put in 2 1/2 gallons, when it ask for it.

sorry for late response been out on the trail.

 

I use a half-gallon pitcher and pour it in slowly.

 

The time to add DEF come again.
Dash warning come at 40% of DEF in the tank, but to avoid annoying message covering other displays, I went to truck stop at 1st occasion.
So using DEF pump, I was able to fill it, but at very, very slow speed. Even at low speeds, regardless the fill tube having venting ribs, the darn things was still foaming over, meaning washing after was needed. Good thing it goes under inner fender, so you don't drive with crystalized DEF on your fender.
Looks to me that buying DEF funnel is unavoidable.
I topped it off till I could see clear fluid around pump nozzle, yet my ScanGauge3 reported 98% of tank after.
I also discovered that my diesel fill has lock preventing gas can nozzle to be used. But then I figured out what the strange tube in my glove compartment is.
DEF was $3/gal btw

 

Good advice - I use the pre-made funnel, I did make my own with the bottle but you have to fill it and press it down so I went for something already made for purpose. I buy the Ford Motorcraft DEF from Rockauto 2.5 gallons for $14. I wait until the DEF fill warning says at least 2.5 gallons to refill then put the whole 2.5 gallons in the tank.

BTW the DEF cap is hand tight not wrenched, that socket hole in the cap to be used for ensuring the correct torque and not over tightening. Whenever I'm under the hood I unscrew the cap and retighten by hand, it can get dried DEF stuck in the threads so make sure it's clean.

 

I ordered funnel for $13 from ECStunning, but will have to see how it works.
Brand bottles use vacuum to stop filling when the level in tank reaches the bottle neck.
Vacuum will not work with open funnel, but then it is having a cap. Then funnel has long "straw" on the end, so if that is used for DEF flow, it is going to be painfully slow.
For me whole point is to fill DEF at truck stop and not have additional mess at house.
Per my observation the whole tank design is screwed, when it has to have very long and narrow neck, not allowing the ribs to bleed the air.
DEF thread and cap are standard and I had the same size in several Mercedes, where filling up was never such problem.

 

The funnel arrived without manual, so the video was very helpful.
From what I see the movable straw adjust the DEF level the tank if filled up to.
Would you happen to know recommendation how far it should be?

 

I'm not 100% sure, but when I get the DEF refill message I just drop around 2.5 gallons in.

 

Pump nozzles go about 3" into the fill pipe, so that is what I plan to adjust. Take tape measure with me next time, to measure it precisely.
But from what I see, the funnel is not good for filling DEF at truck stop. When DEF level comes to the top, I will have some fluid in it, that needs to be emptied somewhere.
Good at home, when you are using jug, where you can put it back, but at truck stop I would have to dump it into garbage can and then have a bag to put the funnel in, to wash it at home.
Nothing is perfect and main point is, that I avoid spilling DEF all over the fender.