Regen frequency
Laughing Gas
Joined: Aug 2017
Posts: 799
Likes: 196
From: Tupelo, MS
I also need to understand regens better. Mine was at 99% and regen began. Dropped to 65% and stopped. It has done that a couple of times when I was watching the dash while driving. I added the dpf % with forscan.
I thought it would go to zero when it started as long as i was driving. But it didn’t. Highway speeds. 60-75 entire time this regen.
I thought it would go to zero when it started as long as i was driving. But it didn’t. Highway speeds. 60-75 entire time this regen.
Posting Guru
Joined: Aug 2015
Posts: 2,399
Likes: 12
My OL soot percentage (forscan) hits 100% and it does a regen. Interestingly, I saw a regen at merely 72% this week. It was at 497 miles since the last regen; I suppose that's just the longest it'll wait.
Keep in mind that enabling the dash DPF percentage is not accurate below 40% or so. It tracks OL soot percent (truncated to 5%) unless it gets low. A real 25% load will show 0%. That's why it appears to drop so fast below 40%. It's really a disservice, as you think the regen is done at 0, but it can keep cleaning the DPF for several miles.
Keep in mind that enabling the dash DPF percentage is not accurate below 40% or so. It tracks OL soot percent (truncated to 5%) unless it gets low. A real 25% load will show 0%. That's why it appears to drop so fast below 40%. It's really a disservice, as you think the regen is done at 0, but it can keep cleaning the DPF for several miles.
Cargo Master
Joined: Aug 2002
Posts: 2,117
Likes: 8
From: Over Yonder, MN
Regens will start every so many miles, I think it's 500, or when the filter is full, whichever happens first. Now, for reasons unknown to me, the DPF doesn't fill nearly as fast in cold weather so most bounce off the mileage regen trigger instead, myself included. That's probably why you are seeing regens start at very low filter percentages.
I can't explain why a regen would stop early, mine only ever stops when the filter gets around 20% or i put it in park.
I can't explain why a regen would stop early, mine only ever stops when the filter gets around 20% or i put it in park.
Cargo Master
Joined: Aug 2010
Posts: 3,221
Likes: 63
Do the newer trucks no longer flash the regen message for 1 second?
Mine is a 2011. Most of the time I miss the regen message on the dash, but I am using an Edge monitor so I see it there.
For 110,000 miles my truck regens on average every 424 miles.
And it is always the same amount of time and miles if on the highway. About 13-15 minutes and 14-16 miles.
Even when pulling my 22k RV and have 0 on the the DPF numbers, it will still regen at that mileage interval.
If I was to go by the fuel mileage drop I would not notice it.
Mine is a 2011. Most of the time I miss the regen message on the dash, but I am using an Edge monitor so I see it there.
For 110,000 miles my truck regens on average every 424 miles.
And it is always the same amount of time and miles if on the highway. About 13-15 minutes and 14-16 miles.
Even when pulling my 22k RV and have 0 on the the DPF numbers, it will still regen at that mileage interval.
If I was to go by the fuel mileage drop I would not notice it.
Tuned
Joined: Oct 2018
Posts: 486
Likes: 2
From: Spring Creek, Nevada
FWIW
Ran the truck to town yesterday at 55mph, 95% DPF, Auto Regen Off (FORScan mod). 1200 miles on the truck.
15 miles later pulled up on the ramp onto I-80 and was told DPF Full/Regen Soon. I immediately switched to Auto (on the move), rolled up to 80mph and enabled cruise. 5 miles later it dropped back to 95% then incremented 5% lower at between 2 and 3 mile intervals until it went to '0' at right around 30 miles total. 30 miles on a full fuel tank and Avg mpg was 14.7. After the regen it showed 13.2 mpg. 5 miles later was back to 5% and at 20% 60 miles later. MPG climbed back to 13.9 by the time I got home. I didn't feel, hear, or smell anything during the regen.
Think I'll leave it in Auto and watch the % to see if I can pick up on when it does it automatically. It's not a big deal but I like my new toys.
Like I said, for what it's worth.. just further confirmation on the function. Posted this on the FORScan thread since that's where the Auto Regen mod was experimented with.. thought I'd post to a more appropriate thread.
Ran the truck to town yesterday at 55mph, 95% DPF, Auto Regen Off (FORScan mod). 1200 miles on the truck.
15 miles later pulled up on the ramp onto I-80 and was told DPF Full/Regen Soon. I immediately switched to Auto (on the move), rolled up to 80mph and enabled cruise. 5 miles later it dropped back to 95% then incremented 5% lower at between 2 and 3 mile intervals until it went to '0' at right around 30 miles total. 30 miles on a full fuel tank and Avg mpg was 14.7. After the regen it showed 13.2 mpg. 5 miles later was back to 5% and at 20% 60 miles later. MPG climbed back to 13.9 by the time I got home. I didn't feel, hear, or smell anything during the regen.
Think I'll leave it in Auto and watch the % to see if I can pick up on when it does it automatically. It's not a big deal but I like my new toys.
Like I said, for what it's worth.. just further confirmation on the function. Posted this on the FORScan thread since that's where the Auto Regen mod was experimented with.. thought I'd post to a more appropriate thread.
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Freshman User
Joined: Aug 2010
Posts: 39
Likes: 1
From: California
My 2017 F450 regens like clockwork at or very near 500 mile intervals (currently have around 44,000 miles). Regen lasts about 25 miles at constant 2000 RPMs on highway. DPF filter rarely reaches 100% full but I do mostly Highway Miles loaded and loaded.
Frankly, I have had zero problems with the F450, actually flawless. I do wonder though why Ford doesn't use the ninth injector systems the competition uses where fuel is injected post turbo into the exhaust stream. It can't be "good" for our 6.7s pushing fuel into exhaust valves pre turbo and manifold all the while heating up everything along the way to the DPF (at least that's how I understand it). If others could explain exactly how the fuel for regen gets into the exhaust stream, I'd appreciate it. Can't help but wonder heating up everything by injecting fuel into exhaust valves is doing anything good for longevity when a ninth injector could do the job directly into the exhaust pipe.
Frankly, I have had zero problems with the F450, actually flawless. I do wonder though why Ford doesn't use the ninth injector systems the competition uses where fuel is injected post turbo into the exhaust stream. It can't be "good" for our 6.7s pushing fuel into exhaust valves pre turbo and manifold all the while heating up everything along the way to the DPF (at least that's how I understand it). If others could explain exactly how the fuel for regen gets into the exhaust stream, I'd appreciate it. Can't help but wonder heating up everything by injecting fuel into exhaust valves is doing anything good for longevity when a ninth injector could do the job directly into the exhaust pipe.
Freshman User
Joined: Dec 2018
Posts: 41
Likes: 0
One thing I've noticed is that if you ***** foot it down the highway at 65 for 20 min it wont regen at all but if you rip at 75-80 for 10 min the regen will be working the entire time and get you about a 5-10% drop per 10-15 min. My advice is same as above, drive it like you stole it.
Senior User
Joined: May 2018
Posts: 452
Likes: 17
From: Corpus Christi TX
BTW the urea injection for NOx mitigation is totally completely separate thing from burning off soot from the DPF (regen). The two are completely un-related as far as process control and implementation.
Junior User
Joined: Jul 2017
Posts: 81
Likes: 0
From: Alaska
Regens will start every so many miles, I think it's 500, or when the filter is full, whichever happens first. Now, for reasons unknown to me, the DPF doesn't fill nearly as fast in cold weather so most bounce off the mileage regen trigger instead, myself included. That's probably why you are seeing regens start at very low filter percentages.
I can't explain why a regen would stop early, mine only ever stops when the filter gets around 20% or i put it in park.
I can't explain why a regen would stop early, mine only ever stops when the filter gets around 20% or i put it in park.
Fleet Mechanic
Joined: Jan 2005
Posts: 1,784
Likes: 8
From: Tomball, Tx
Unless I am mistaken, (possible) the DPF regen is a result of diesel being injected in-cylinder(s) on the right hand bank of cylinders, and EGR is raw exhaust piped into the left-hand bank of cylinders. So the turbo COULD see the extra fueling being applied to do the regen. I think the GM regen they inject diesel into the exhaust downstream of the turbo. Boost indication would confirm this. On my 2011 I once owned, I could bring up the instantaneous fuel mileage bar graph and it would very graphically display when in regen. It sucked watching that mileage just fall off a cliff when it went into regen. Every 500 miles. Although I don't remember seeing boost elevate intra-regen...
BTW the urea injection for NOx mitigation is totally completely separate thing from burning off soot from the DPF (regen). The two are completely un-related as far as process control and implementation.
BTW the urea injection for NOx mitigation is totally completely separate thing from burning off soot from the DPF (regen). The two are completely un-related as far as process control and implementation.
in fact my experience is different - IF you run hard the regens will take LONGER - but they still occur. I believe fuel consumed by the ENGINE prevents fuel for the regen.
based on monitoring of the 4 EGT sensors - the additional heat (aka fuel) is being injected further down stream, post turbo.
Fleet Mechanic
Joined: Jan 2005
Posts: 1,784
Likes: 8
From: Tomball, Tx
In monitoring my CTS unit this morning driving to work, my DPF% dropped from 64 to 56, over a 6 mile drive. Speed never above 50, ECT never above 130, EGT1 (at the turbo) only briefly above 500. Outside air temp, 18F. Nothing that would be considered a regen in process, the % just started dropping. This is not the first time I have seen it drop, when the temps did as well. Kind of wish I had a few more miles on the commute.
its unlikely that you've gone 1250 miles without at least TWO regen's.
how do you KNOW its not regen'd? or better still how do you know when it IS regen'ing?