The last thing the salesperson told me after I had done bought the truck, and she had got thru with her Tutorial she told me about the mandatory EPA and DEF requirements.

I said, "What!! You didn't tell me that up front." What in the heck is DEF fluid?
She said you have to put special fluid in this port. 6 quarts of DEF. Don't let it run empty.

Well, I did not do my homework prior to buying. No one to blame but me on that.
All I knew prior to buying a Diesel engine/vehicle was that diesel cost more than regular grade gasoline.
After reading the diesel supplement book I find out it ain't 6 quarts but 6 gallons. Good Grief.
I already own a diesel Kubota tractor. But it don't need nothing special.
Well now I'm an owner of a Ford F250 power stroke so I guess I better get use to the cost to maintain it I guess.

 

How often does the DEF tank need filling?

 

welcome to db
technicaly, they say you will need to fill it at every other fill up.
My work truck has it and i hate it.