Some anecdotal evidence to put in the hopper.

I manage HV maintenance at my factory and I just ran our annual 138 kv substation maintenance outage. Had a dozen field service engineers from multiple companies working on all kinds of equipment. Two engineers from one testing company had 6.7's. The guy I talked to in some detail had a 2015 6.7 XL fleet vehicle with over 160K miles. Had a lot of heavy gear in the 8' bed. No serious issues with his rig over that mileage, but noted that he finds differences in DEF mileage. He figured out early on that he got better DEF mileage with Blue DEF vs. cheaper generic DEF. Could it be that cheap DEF is the cause of some of the issues we read about here?

His lease company requires oil changes every 7500 miles which did at dealers around the country. Does not wait for the computer to tell when to change oil.

He idles his truck a lot just to stay alive in places like northwestern Iowa in January. But also puts a ton of mileage on to get to 160K in that short time. Wanted to circle back and talk to him more but was just buried in equipment and personnel issues.

I think there are a lot of these examples out there that we never hear about and never will 'cause everything just works.

 

DEF is DEF. the amount of time/miles between replacement depends on usage.


In the winter he would use less as it is frozen. Once thawed then it becomes available for use.


Towing/heavy loads will use more def then unloaded miles.


All def has to be made to spec. There are no additives or anything.


I think in this case he does not understand how it is used.

 

See the Fueling and Refueling section of the 2016 Ford Diesel Supplement manual that came with the truck. It tells one about the approximate usage of DEF for different conditions.

Find the owner's manuals here

Owner Manuals | fleet.ford.com

 

Thanks for responses. So "Blue Def" is only marketing schmaltz?

 

Speaking of differences in DEF, while traveling through southern Idaho, I stopped by a Ford dealer in Mt Home to get a 2.5 gallon jug of DEF. This dealer also sells Dodge. He asked if I wanted Mopar or Ford. I ask what's the difference. He said about $7. Ford $15, Mopar $22.

Rob

 

I get the cheapest there is.

 

IF the DEF is OLD then you could use more of it. The computer reads the exhaust and injects DEF as needed.. Old DF doesn't work as well as fresh DEF. Otherwise, I agree, DEF is DEF.

If the DEF is exposed to sunlight or high temps it loses it's effectiveness a little quicker.

The quality of the fuel you use or if you run BioDiesel can affect DEF MPG too. I run the bulk stuff when I can and I got lucky enough to find some blueDEF on sale at Walmart for $8 for the 2.5 gal cube last time I needed some.

 

Or at 160k just delete it all, get all the benefits or more power and better mileage and forget about the DEF.

 

I have purchased DEF a few times from FORD. Always got it by the case and it says Motorcraft on the box. I was in Canada in August passing through Whitehorse, Yukon and at a Ford dealer there they sold Blue DEF. They told me that's what FORD sends them. So I guess in the end it really doesn't matter so long as it's fresh stuff.