DEF Tank & MPG

[Bob Denman]

Your DEF tank access would be a dream come true for us...
(Under the hood: in the engine compartment. )

[EA37TS]

Originally Posted by paulwadley

Bob

I have been ordering it online at Amazon and it comes to the house. No need to go out looking for it.

Paul

Can’t verify the date code with Amazon or determine storage conditions.

[Bob Denman]

Is the stuff really that fussy?

[EA37TS]

Originally Posted by Bob Denman

Is the stuff really that fussy?

https://www.peakhd.com/lifeblood/fluid-thinking/a-guide-to-def-storage-contamination/

[Bob Denman]

Thanks!

[paulwadley]

The last two gallons I received were produced in 2020. Guess I have been lucky with the purchase. One thing I admit is that I can not determine how it was stored before I received it.

Paul

[Bob Denman]

... probably in the back of a trailer that has been left at a truck stop just outside of Macon...

[EA37TS]

For those that might be interested the November 2020 issue of Family RVing magazine, which arrived in the mail yesterday, has a decent article on DEF. The article explains what DEF is, how to handle DEF and how DEF is used in a motorhome to include tanks, gauges etc...

[alajeu]

Originally Posted by EA37TS

Diesel Exhaust Fluid. Used in emission systems of newer diesel engines.

Thank you. I am not a fan of Anachronisms

Alajeu

[simidrm]

Typically def consumption is around 2% of the amount of fuel= 2gal def per 100 gal fuel,
but as the system age's that will gradually increase a little, def consumption is controlled by the ecm and doses the amount of def to the nox level in your exhaust so as the system ages it becomes less efficient and consumes more def to achieve the 80% reduction in nox from the inlet to outlet of the system.

[simidrm]

Acutally inside the def tank is a concentration sensor that measure the amount of urea in the def and unless it is 32% or more of urea it will set a check engine light and reduce power of the engine,and washer fluid will not work as I have had alot of people try it and it will void the warranty

[Bob Denman]

Can you just pee into the tank; in order to up the urea concentration?

[Bob Denman]

Originally Posted by simidrm

Typically def consumption is around 2% of the amount of fuel.

So if you multiply your fuel mileage by 50: you should be pretty close on your DEF mileage.
For my rig: 14x50 equals 700 mpD.
Since I've got a 4.8 gallon tank, and want to keep it at or above 1/2 full: I should re-fill at about
1,680 miles...

[paulwadley]

I can go about 1400+/- miles on half of my DEF tank. I try to fill it around that mileage plan and it usually takes 2 to 2 1/2 gallons to fill it to the top. I have a Sprinter Chassis motor home.


Paul

[Bob Denman]

Paul,
What sort of fuel mileage are you getting?
(Trying to sort out that 2% rule...)

[paulwadley]

If I stay around 65 mph I usually get 13-14 mpg fuel economy.


Paul

[Bob Denman]

So if we use 13 mpg for your situation: that would work out to re-filling at 1,560 miles...
Okay: it's not quite at the 2% mark...