If for no other reason, throw a couple jugs in your truck and drive it until you've got less than 100 miles to empty just so you can see what it does. I've taken mine down to zero just so I know what would happen. Believe me, you will see how much warning you get before it shuts the truck down.

 

I've been wondering about my DEF for a while too.....

Shortly after I got the truck I got the "less than half warning", maybe less than 2000 miles on it at the time.

Not knowing any better, I bought a 2.5 gallon jug and filled it up... I think. It took the whole jug and the screen said DEF level ok afterwards, so I didn't add any more.

Now...... several months later and just rolled 7500 miles on it .... it's saying under half full. It's been saying that for a couple months and thousands of miles though. ????

I'm waiting for the less than 100 miles countdown this time.

Just odd that at 7500+ miles, still showing to have DEF. But most of my miles are highway miles and regens clean it out really fast... according to my Torque app anyway.

I hate to buy a jug "just in case" as I already have a jug I bought last fall that's probably expired by now.

Been stored in my foyer closet (dark and climate controlled), but still getting older by the day. Need to check the date code I guess.

 

It's tough to do since DEF freezes.


Best bet to keep the system from being confused is to wait to fill once it gets down below 500 miles to empty. Ford designed it to be something that is almost completely invisible until it's almost time to fill. Problems happen when owners try to do things different than what Ford designed.

 

With the right highway driving you can get close to 9,000 miles on a single tank of DEF.

 

This is true. I made sure the dealer topped mine off before delivery with 5 miles on the odometer, and I didn't get the 500 miles to empty countdown until 8,700 miles. It had not been topped off during the dealer performed oil change two weeks prior to getting the messasge. Ford designed the tank to be able to last close to the interval for an oil change. It worked well for me.

 

That's good to know.

I'll be towing my 13k lb 5th wheel 200 miles tomorrow and back again Monday. Then out again next Thursday (June 2) for 300+ miles one way, then back on the June 12th.

I'm hoping the remaining DEF will be enough and passive regeneration will keep it from going into a regular regen.

I've got a jug of Peak Blue DEF. Just checked it and it's not sealed under the cap. Are they supposed to be? Looks like I might have tried to top off with it and it wouldn't fit.

It's got this code on the side of the box. Anyone know how to decipher it?

12161401714

 

Towing actually forces more DEF usage, and less regens.

 

YUP. DEF use is linked to fuel use.

--

Decoding Blue DEF:

The date code on the BlueDEF box is

GA153590089

Lets break this down into 4 groups of numbers:

GA: The designator of the plant that manufactured the DEF
15: The year of manufacture plus 1, so this DEF was made in 2014
359: 365-359 = 6, so the 6th day of the year, or January 6th.
0089: The batch code.

So this box of DEF was made January 6th, 2014.

 

I've bought several jugs of DEF. All but one has been sealed. I took it right back to the store and exchanged it. I'd do the same thing again if I got another one like that. People have really warped senses of humor anymore...

 

Probably put water back in the jug and returned it... I never buy refrigerator filters that are not in a tamper proof container and sealed.

I used to only get DEF in bulk at the station, but there isn't an easy place to do that up here in AK.

 

Ok. I guess I had it backwards in my brain.

I thought DEF was used during an active regen with the extra fuel being pumped into the exhaust.

I thought during heavy towing, the heat alone burned off the soot.

I'm going to get a new, sealed, fresh jug of DEF to carry with me during my heavy towing the next few weeks.

Thanks guys. Sorry I hijacked this thread.

 

heat does burn the soot...so fewer regens during towing.


does nothing for the Nox, which is what the SCR does. In the towing situations you would have more gases to deal with.


That is why I only get about 4500-5K per tank of def.

 

There may a way Ford could do an very accurate DEF gauge... or maybe Curtis will tell me why this is nuts... Right now it uses 3 sensors that got through the tank and the DEF itself closes a circuit based on how many sensors are in contact right? Kind of like an RV holding tank with it's 3 sensors for empty, 1/3rd, 2/3rds, and full. How about a more modern outside the tank sensor that doesn't have to make contact with the DEF at all. I was investigating the SeeLevel monitor system for an upgrade on my RV tanks. It's a tape like segmented monitor strip sensor that is attached to the outside of the tank and reads in % increments. Much more detail than the 4 levels that the old school sensors read. (And on an RV black tank, won't get false readings due to last night's dinner sticking to a sensor...) Couldn't something like this work as opposed to through tank sensors or floats?

If it's hard to picture what I'm talking about, click on the instruction manual on the products website.

https://www.garnetinstruments.com/pr...-tank-monitor/

 

Rodney, I agree something could/should be done to make it better, even if they had to put more sensors in the tank. Part of the problem is that DEF freezes. Floats and external sensors may not work. Also, the DEF tank can't allow light to get in because sunlight degrades DEF as well....

When Ford expanded the gas tank for 2017, they could have (maybe they did?) expand the DEF carrying capacity as well. The 5 gal DEF tank doesn't last oil change to oil change as was the original goal. A 10 gal. tank, even for those that tow all the time should. (or at least is would for 95% of us). I've gotten as low as around 600 miles per gal of DEF and as high as 1100 by hand calculating.

It's funny - but something as simple as a scale that keeps track of the weight of the tank could work too...

 

Floats wouldn't work but an external sensor shouldn't be affected by freezing? I'm sure Ford thought of everything I have so there must be a good reason though. The scale idea is interesting too. Let's call Ford and pitch our ideas Dak...