When to add DEF (By the Jug)

[Bombdigitty]

Any thoughts on this? At what point will a full jug fit in the tank. Father In-laws Eco Diesel will take a full jug when the gauge reads 1/2 tank.
Thanks for your input.

 

[RPS1030]

Pretty much the same. About 1/2 on the gauge, put a jug in.

Listed as 5 gal capacity I believe, so getting 2x 2.5 gal in can be done when it’s way way low.

But it was less stressful for me to just do a single jug whenever it was around the 1/2 point.

New house puts me a couple miles from a Maverick with “Truck/RV” lanes that has DEF pumps on some of them, much much better. Old house was nowhere any pumps.

 

[Bombdigitty]

Pretty much the same. About 1/2 on the gauge, put a jug in.

Listed as 5 gal capacity I believe, so getting 2x 2.5 gal in can be done when it’s way way low.

But it was less stressful for me to just do a single jug whenever it was around the 1/2 point.

New house puts me a couple miles from a Maverick with “Truck/RV” lanes that has DEF pumps on some of them, much much better. Old house was nowhere any pumps.

Oh good. Thanks for the reply.
I've only used 1/4 tank so far, so ill hold off for a while longer.

There are no def pumps near me. I dont know of any in Canada. Maybe at the bigger truck stops, but havent seen any yet.

 

[MtnRider]

Oh good. Thanks for the reply.
I've only used 1/4 tank so far, so ill hold off for a while longer.

There are no def pumps near me. I dont know of any in Canada. Maybe at the bigger truck stops, but havent seen any yet.

If you are not towing the DEF burn rate will be pretty slow (and the gauge is not linear). When around town I just ran it until the low DEF light came on then added a 2.5 gallon jug which took it to a little over half. That way I didn't have old DEF sitting in there a long time. If towing or going on a long trip I would fill it up.

.

 

[sstoner911]

I usually wait to about 1/4 of a tank left on the gauge. This guarantees I wont be over filling and dumping it all over he side of the truck. If I am towing I may wait til the DEF light comes on and then I can get almost 2 full jugs in. I wish there was a good reliable way to gauge how close you are to over filling before it spits up all over the place!

 

[Brutal_HO]

Depends on the weather.

In winter I add a 2.5 gal jug when the def low comes on or @ ~1/4 when I expect more usage. Don't want a 5 gal iceberg to thaw if it comes to that.

In summer during towing, I add a jug when it falls below 1/2.

 

[diesel_driver_3500]

I thought the DEF tanks held 5.5 gallons? I fill when it reaches 1/2 tank. That way, I should always have room for expansion (1/2 gallon), and never overfill it.

 

[sstoner911]

I thought the DEF tanks held 5.5 gallons? I fill when it reaches 1/2 tank. That way, I should always have room for expansion (1/2 gallon), and never overfill it.

I don't think the gauge is always accurate....I have filled at 1/2 and sometimes it won't take a full jug... I'll have maybe 2 in of DEF left in the jug...

 

[Brutal_HO]

There's a TSB that specifically warns against overfilling the DEF tank. The (sonic?) sensor needs air space in the tank to work properly and can cause issues if overfilled.

 

[Millmutt]

I fill at the pump, haven’t ever used a box or jug, never had an issue.

 

[sstoner911]

There's a TSB that specifically warns against overfilling the DEF tank. The (sonic?) sensor needs air space in the tank to work properly and can cause issues if overfilled.

Meh, they really have no idea if its an issue to overfill.... What is over filled? Just when it pukes out all over the truck or just above full or under full?? Where is the sensor located exactly?

My 2017 was deleted so DEF was a non issue. On my 2019 and 2021 I have filled until it is full and puked out the fill tube and never had an issue so far. For a tank that has no real mechanism to indicate when its full or to full while filling - its a crap shoot I guess.