Hey gang. As I posted earlier we picked up a 2014 F250 Lariat 6.7. I understand that I should wait until the truck tells me there's x miles till empty. Is this correct? If so when it says x miles.. How much DEF will it hold? Thanks

 

Correct. Fill the DEF when the truck goes into the mileage countdown. This helps prevent the system from becoming confused on whether or not it's full.

Once it reaches the countdown, it's going to take around 4.5 gallons give or take.

 

Thanks. I wish Ford had this. From my 2018 Freightliner Evolution.

 

Ford has a fairly accurate gauge on the 2017+ trucks...

 

Yes. Don't overfill in the winter time. Other than that, maintaining DEF is simple. I drive it for a bit after the 800 MTE is thrown and fill at a pump.

 

I fill mine when it gets to the 200 or less count down.

 

i generally fill mine with it is less than half full. I use the Ford DEF nozzle. This helps prevent over fill and DEF on the truck paint. Never have had a problem with the DEF resetting to Full almost immediately after filling.

 

Is the Ford DEF nozzle the same thing as the nozzle on the 2 1/2gallon jugs?

 

No. The ford nozzle locks into the filler hole and won't come out like the one that comes in the jug. However after use I rinse mine out because DEF will crust up when dry and you dont want that in the tank. Get it at the dealer they are not that expensive. I keep mine in the bag and put that in the center console because I travel a lot and never know when I need to fill up.

 

I also wait till the 200 mile warning. I buy 2 5-gallon jugs from Ford which the truck takes a bit after I get the 200 mile warning. I also use the Ford filler tube.

 

The Ford DEF Nozzle PM-27-N fits most all DEF containers.


The crusted DEF will re-dissolve when wet. It does not stay a crystal when liquid is added or wet by DEF.

You can buy the Ford DEF nozzle on eBay for like $6 with free shipping.

https://www.ebay.com/itm/PM27N-NOZZLE-ASY-Ford/302762375660?epid=1528890217&hash=item467e0b39ec%3 Ag%3AUUIAAOSw8lpZNp4j&_sop=15&_sacat=0&_nkw=pm-27n&_from=R40&rt=nc

 

It all depends how many times you want to answer the message at each start!

 

I have a 2016 that might not have the issues like the earlier models do. I check the message center at fuel stops and when it reports "under half" I fill it up. Never had an issue with the truck complaining about no DEF in the tank.

Another interesting fact. I use Torque Pro to monitor my regens and noticed the last time I filled the DEF tank Torque Pro has been reporting 3.1 gallons in the tank. It has not changed in the last 1000 miles or so. I assume it will not change until one of the sensors reports it's lower than 3 gallons.

 

 

The DEF tank sensors are non-linear for the 2011-2016 trucks. There are 4 prongs that compromise the level sensors. One is a ground, one is for full,one is for half full and the last one is for the count down. There is no way to accurately measure the DEF % with any programmer/monitor. The last time I tried to use TorquePro, it gradually went down to 66% and next thing was the count down message on the screen.

As your owner's manual states, the DEF is used at a varying rate depending on your usage of the truck such as, around town, cruising, towing or towing heavy.