Up until a week ago, i could run at highway speeds for about 20 minutes and the dpf gauge reading would start to drop 5% every few minutes afterwards, and then continue to drop to either 0% or 5%
i took two trips of 60 miles at 75 and above and the dpf gauge never changed, it stayed at 70%, climbed up to 80 at a red light, then once back on the road the gauge dropped back to 75 and never changed.
then the trip home from the highway is around 27 miles at 65 to 70 and it never moved.
pulled in driveway after the nearly 3 miles in the neighborhood of 25 mph to get to my house the dpf went up to 90%

only thing different is FUEL brand. i had to fill up at murphys (wally world), we are talking over 3/4 of tank.
and......usually once on highway at sustained speeds of 75 or higher, the instant mpg climbs really fast from 18 or so to 22 plus. its not doing that either and is stuck at 19
is it possible the murphys fuel is causing the issue? it does not have bio in it and i have been running QT fuel which is b20 since the 2nd tank of fuel in april when i got the truck
just bouncing this out there
and of course weather has been 41 to 50 in the am and 75 or so in afternoons, the trips were around 60F

 

Murphy is usually at least 10% bio or it is at Wal Mart Murphy stations. I doubt the fuel is the problem it there is actually a problem. In my 2015, you had to exceed 700* on EGT #4 for passive regens. Do you have any way to see what the temp for the temp probes in the cat/dpf? You maybe not have had enough temp to burn the ash out of the dpf to drop the percentage. I monitored EGT #4 on my 2015 to see if it was high enough to do passive regens.

 

walmart murphy. no bio in it as stated on the pump, but their website listed our area as b5.

i plan to use the forscan data logger on an upcoming extended 8 to 9 hr drive next week to see what temps i am actually getting at the dpf and the whole list of probes.
i think its just not getting hot enough, i still cant believe it runs 185 to 195 on water temps
i am sure after 4 hrs straight at 77 at a time it will clean out .
its just one of those things i was really paying attention to as i was only one in truck and got bored

 

No problem here.

I would just say it didn't get hot enough for EGT 4.

 

the only fuel type variable that I can think of is

brand “a” is normal= normal things should happen

brand “b” has a crane boost I. It or is higher crane rating.

brand “c” is a bio blend. Bio fuel has a lower btu value and presumably burns at a lower temp. Exhuast temps lower.


any combination of the above

air entrapment conditions…usually running tanks low . Micro air bubbles changes ignition timing which results in combustion timing control variables.

 

I just went to Oklahoma and back home last weekend, after fueling in Amarillo my mileage dropped 20 % used about normal DEF but didn't show gains from passive regen. Fueled in Weatherford, same bad mileage and no gain during passive regen, fueled in Amarillo same low mileage and no passive regen gains. fueled in Albuquerque, mileage back to normal and passive regen showed lower dpf level.
I have gotten (weak) fuel in Amarillo before in my '97 and literally couldn't get the exhaust temp over 800 degrees. I am thinking they already have their winter blend and possibly has bio in it.

 

I would turn auto-regen off, let it get to 100% then do a static regen somewhere safe and let it really clear it out, then see how it performs afterwards?

 

I know in our part of the world. All the refineries start producing a winter blend in October. My fuel mileage always drops by the first of November as it gets distributed and replaces the summer blend. And there is no Bio in Winter blend diesel. After watching the fiasco in Texas last year, I'm not sure you guys get a winter blend. Also I know some areas of Texas get 50 Cetane diesel. Maybe you just got a tank of 40 or 45 cetane The higher the Cetane, the more complete the combustion, hence less soot.

most of the time the passive regen won't keep up with the soot production. If you are working the engine, a head wind, climbing a grade, accelerating all produce soot faster than passive can deal with it. Just a gentle drive on a flat road, Doesn't get EGT temps high enough for Passive Regen.

 

i am hoping we dont get messed about here in north east texas with fuel this early
most of the stations around us (100 miles) get serviced from tyler fuel depot, not sure if that depot is from houston or south la.

mpg is important , but not the biggie factor

dpf not clearing out to 5 or less bothers me as its out of the norm.

we dont have the luxury of a commanded regen, so i have to wait to 100 and see if it does a commanded regen by the ecm
i have along trip coming up and really hoping i can get good data on temps.
might drive with 9 and 10 locked out next trip to town (20 plus miles) .

 

I may have missed what year your truck is? I used forscan and turned on my DPF% screen and the setting to turn off auto-regen on my 2019

 

heavy towing and EGT 4 in the 800's will allow for passive regen even if you are heavy towing and producing a lot of soot.

I think that the fuel/blend is probably the issue.

 

I am guessing the truck just isn’t working hard enough for a passive regen. I know when towing I can watch the dpf level drop. When not towing it’s barely breathing and no passive regen is happening.

 

I've never seen my truck passive regen, even towing the camper. Truck doesn't seem to get hot enough long enough to passively regen when unloaded and our camper is relatively light for the truck. I do run Hot Shots fuel additive so I'm thinking cetane isn't the issue, just not working the truck hard enough.

 

Why would you do that? Running at a lower gear increases the rpms, Which in turn increases the amount of air thru the engine.
My experience is that reduces the EGT's You get hotter EGT if you load the engine at lower rpms.

Watch your egts. I'll bet they are hotter in 10th gear at 70, than in 8 gear at 70 pulling the same stretch of road.

 

And this thread goes to show why Ford eliminated the DPF screens for the owner. Unnecessary worrying over nothing. Just drive like normal.