I would take it to the dealer. I don't know what the smell is because you have to be going 35 or faster for the regen process to happen. People are going crazy watching the regen process. You may want to check the air filter. Mine was dirty and the valve on the side of the box showed it was ok., I would not worry so much about the regen process. To many variables.

 

First off, did you read your owner's manual about regens? There is usually a lot of info one can gleam from it. Ford didn't write it to be dead weight and occupy all the space in the glove box

You have active and passive regens. Passive regens happens when towing, The exhaust temps are high enough to burn off the ash build ups. The Filter full % may never reach 100% due to the passive regens.

Regens are still set for 500 miles max since the last completed regen.

To me, sounds like the truck is regen'ing properly and as designed by Ford. The smell might need to be checked as it might be from something else besides regen.

Page 200 in owner's manual

Passive Regeneration
In passive regeneration, the exhaust
system temperature and constituents
automatically clean the filter by oxidizing
the soot. Cleaning automatically occurs
during normal vehicle operating conditions
due to driving patterns.

Active Regeneration
Once the diesel particulate filter is full of
exhaust particles, the engine control
module commands the exhaust system to
clean the filter through active regeneration.
Active regeneration requires the engine
computer to raise the exhaust temperature
to eliminate the particles. During cleaning,
the particles convert to harmless gasses.
Once cleaned the diesel particulate filter
continues trapping exhaust particles.

Page 201

The regeneration process operates more
efficiently when you drive your vehicle at
a constant speed above 30 mph
(48 km/h) and at a steady engine speed
for approximately 20 minutes. The
frequency and duration of regeneration
fluctuates by how you drive your vehicle,
outside air temperature and altitude. For
most driving, regeneration frequency varies
from 100–500 mi (160–805 km) between
occurrences and each occurrence lasts
9–35 minutes. You can usually reduce the
duration of regeneration if you maintain a
constant speed above 30 mph (48 km/h).
When the engine control module detects
that the diesel particulate filter is nearly
full of particulates and you are not
operating your vehicle in a manner to allow
effective automatic regeneration,
messages appear in the information
display as a reminder for you to drive your
vehicle in order to clean the diesel
particulate filter. If you drive your vehicle
in a manner to allow effective automatic
regeneration, the information display
shows a cleaning exhaust filter message,
which is the normal regeneration process.
You can also choose operator commanded
regeneration to clean the exhaust system
at this point. See Information Messages
(page 127).

 

I agree with Larry the regens appear to be working as designed. This might be one reason Ford does not enable the DPF % by default, it can be confusing to a driver that doesn't know how the DPF works. The smell is not right, might need to have that looked at.

The MPG you are reporting is a bit low for a 6.7l 4x4 SRW with stock tires. I know the earlier 6.7L got a bit better mileage than I currently see, might be true for the newer trucks with more HP and Torque. My 16' with 20" Toyo AT2's 3:55's in tow haul mode will get 10mpg towing a trailer of similar size as yours but a bit heavier at 6500lbs with a combination of city and highway driving. Highway only with this trailer is around 12mpg at 70-75. Towing my 6500lbs travel trailer the mileage is not as good due to the added height and length. I can get 11mpg hwy @ 65 with the travel trailer or 9mpg @ 75.

Maybe your travels include more mountains and that is the reason for the lower mileage? On your next trip out try slowing down to 65 for the trip and see if your mileage doesn't jump up a mile per gallon or two. If the mpg don't jump up after slowing down to 65 then maybe you do have a DPF issue of some sort.

 

I had an odd smell from new to about 20k or so miles. Smelled like burning paper/wood. Exhaust gets really hot and what ever it was that smelled, it took a lot of regens and miles to finally stop. Now with 26k, I cannot smell the regen process.
There will be some unusual smells for a few thousand miles. More noticeable at low speed and stops if regen is not complete.

There are a couple of paper wrapping, for lack of a better word, on parts of the exhaust that have part numbers and other info on them, crawl underneath and take a look. They heat up and smell. Eventually they loose all smell but takes a few thousand miles.... 20k or so...

I average 10-11 mpg on my fifth wheel (yuge frontal area), 34 foot, 14k lbs. Your mileage seems really low for a light weight low profile v-front trailer

 

There are also past cases where trucks smell bad during a regen because of exhaust leaks. I don't know if this still applies to your newer version truck, but there was one spot on the passenger side by the front of the cabin where an exhaust connection may have leaked some. Your dealership should find this if you take it in. My truck had a similar smell during regen, but it turned out to be a leak somewhere in the front section of the DPF assy. It was the last thing in a series of troubleshooting checks, and after the dealership went through all the previous troubleshooting steps over a couple visits to the dealership, Ford ended up sending the dealership a new DPF assy, which fixed the problem. Yours sounds pretty bad.