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DEF milage and general emissions comments

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Interesting thread. Have never tracked our DEF economy, but now see the benefit of knowing a baseline and watching for a change.

I also use box DEF and I like top off the tank at my leisure and convenience and not when Im getting fuel, so I will buy enough for a trip and carry it with me. I can also better control the price I pay this way, having found it at $25 for a 2.5 gallon jug at many locations.
Rich, curious about your comment and like to learn. You mention the “convenience and not when I’m getting fuel”, this makes me realize that I am oblivious to something, have a few screws loose or some might say, both.

Wondering about your coach setup and how going to a store on a separate trip to buy DEF and then storing it is more convenient then just grabbing a pump handle for bulk DEF at the truck stop? Only 1.5 years into RVing and still learning.
 
Interesting thread. Have never tracked our DEF economy, but now see the benefit of knowing a baseline and watching for a change.


Rich, curious about your comment and like to learn. You mention the “convenience and not when I’m getting fuel”, this makes me realize that I am oblivious to something, have a few screws loose or some might say, both.

Wondering about your coach setup and how going to a store on a separate trip to buy DEF and then storing it is more convenient then just grabbing a pump handle for bulk DEF at the truck stop? Only 1.5 years into RVing and still learning.
For me def is a pain at pump since it’s at rear right of my Dutch star, most pumps have def only on driver side so I need to pull fwd and hope the guy before pulled out far enough and then get the pump across somehow and then hope the guy behind understood why I pulled up and am still there. If all that aligns I have to hope the pump allows def after fuel and some do it the other way for some weird ass reason.
 
Interesting thread. Have never tracked our DEF economy, but now see the benefit of knowing a baseline and watching for a change.


Rich, curious about your comment and like to learn. You mention the “convenience and not when I’m getting fuel”, this makes me realize that I am oblivious to something, have a few screws loose or some might say, both.

Wondering about your coach setup and how going to a store on a separate trip to buy DEF and then storing it is more convenient then just grabbing a pump handle for bulk DEF at the truck stop? Only 1.5 years into RVing and still learning.
Well yes, pump DEF would be more convenient in some cases if I used it, but I don’t. Also my DEF tank is in the rear on the driver‘s side, and my fuel fills are 30’ away in the front on both sides, and I rarely line up with both a fuel and DEF nozzle at the same time.

I fuel on the passenger side as often as not, and would most often have to move the rig to get a few gallons of DEF. Also I now keep the tank full (to keep my DEF header happy) topping it off in 2.5 gallon increments as soon as the dash gauge reads 3/4, and this usually doesn’t coincide with fuel stops.

I don't use bulk DEF because two of my mechanically disabling DEF related events occured directly after using DEF from a pump. It might have been coincidence, and call it superstition if you want - I wont use it for the coach. I verify date codes and storage conditions before buying DEF, and I test with a refractometer before dumping the stuff into my tank. Lessons learned the hard way dealing with a fragile emissions system. By comparison, my Ford 6.7 can apparently use any DEF without issue, and the DEF and Fuel fills are both in the same location. So it often gets pump DEF.

I can easily carry enough DEF to cross the country and that keeps me from needing to buy it at opportunistically high prices on the road. I like to top off the tank at my liesure in a campground while doing other outside chores, rather than hassle with it while fueling, when there is usually a lot of other stuff going on and truckers waiting for fuel.
 
This is one way I dealt with box DEF (and sewer hose) storage:
Before:
BA623B39-8342-4C53-BFFC-A612F2EDB045.jpeg

After


1657CE68-A6B7-4062-8795-72D58C359057.jpeg

Three boxes easily fit here. The Active Air valves prevent a forth unfortunately, but on my last trip I carried two more elsewhere. Really made it convenient for me to top off any time, any place I wanted.

DD3BE007-D691-481D-B283-F2521E0323CF.jpeg

Originally I designed this space for “NED“ but I benched him in favor of a mounted tankless compressor, so that made room for DEF.
0D616E42-921E-4EF7-B1FA-051AFA312DFD.jpeg
 
When using boxed DEF, learn how to read the expiration date codes and speculate on how the product has been stored. Quite a short expiry on DEF.


Additionally do not buy an unsealed box. Reports of customers buying, emptying the DEF, refilling with water and return to the store.
 
I finally decided to add DEF and could have gone much further. I left this trip full DEF and went from Richmond, VA area to Virginia Beach, back to Richmond, VA and north to Newmar. Then west to SD and now in SE Denver area (Aurora) and there is a T/A not far from me so I figured I'd top off diesel and def before my next stop entering the Rockies. I had 2 dots of DEF still showing which is amazing, very efficient. At the tank it was showing 3/8's of a tank remaining. I wanted to get as much of the aged DEF out to fill with new, I've been mixing new/old for 5+ years now.

Added 8 gals which comes out to 300 MPG of DEF
 

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