If you are traveling at highway speeds and pulling a #10,000 load, does the regen cut in? I am looking to buy a newer truck and not sure if I will go to the Lbz or Lmm.
I know that when it burns off that it uses more fuel, but not sure if it would carbon up at highway speeds.
Also can you install a programer for more power and mpg, but would that cause more carbon build up and more regens?

It regens every 425-450 miles regardless of speed/empty/loaded in my experience.

There are "clean" tunes out there like Banks.....

Yes as stated in above post
Are you asking if it's detrimental to your towing power? No
l think Edge also just came out w/a "clean" tune, I've done no research on that one.
Hope this helps.

If you are traveling at highway speeds and pulling a #10,000 load, does the regen cut in? Yes That's what i meant to answer in the first reply.

My understanding is that the regen process works best when traveling at highway speeds. Not sure what you mean by "cut-in". It will "carbon up" if regen is not allowed to occur at all (i.e. extended idling periods).

I recently took a trip to the midwest; left with just over 700 miles and returned with just under 5,000l miles. Mostly highway travel; I never saw a Regen come on. :eek:

I recently took a trip to the midwest; left with just over 700 miles and returned with just under 5,000l miles. Mostly highway travel; I never saw a Regen come on. :eek:


The regen process is virtually seamless unless you have some type of monitor such as an MSD DashHawk, etc. One way you can tell if your truck is in regen is if the avg. mpg takes a dump from say 15 and goes way down. I've been paying close attention to mine and although some might call it weird, I can actually hear a difference in the sound of the motor, and have gotten out before and confirmed it was in regen by the scorching exhaust temperatures. :eek:

I recently took a trip to the midwest; left with just over 700 miles and returned with just under 5,000l miles. Mostly highway travel; I never saw a Regen come on. :eek:


10 regens slipped right by you........ Sneaky arn't they.. :D

10 regens slipped right by you........ Sneaky arn't they.. :D
:D:D:D Ya gotta pay attention...

The regen process is virtually seamless unless you have some type of monitor such as an MSD DashHawk, etc. One way you can tell if your truck is in regen is if the avg. mpg takes a dump from say 15 and goes way down. I've been paying close attention to mine and although some might call it weird, I can actually hear a difference in the sound of the motor, and have gotten out before and confirmed it was in regen by the scorching exhaust temperatures. :eek:
I agree that sometimes when it is in regen, I can hear a very slight difference in the engine sound. I can also sometimes smell it.

As for the mpg on the DIC in regen, if I am cruising at 60 mph and reset the DIC during a regen, it will show between 11 and 13 mpg. I also get my very best mpg on the DIC immediately after the regen is finished.

I agree that sometimes when it is in regen, I can hear a very slight difference in the engine sound. I can also sometimes smell it.

As for the mpg on the DIC in regen, if I am cruising at 60 mph and reset the DIC during a regen, it will show between 11 and 13 mpg. I also get my very best mpg on the DIC immediately after the regen is finished.


Agreed - And it runs stronger and responds quicker at those EGT's near 1,000 degrees. :D

Mine just went into regen this morning 5 miles into my 8 mile commute - as expected right at 424 miles since the last regen - with a soot level of 22. So it barely had 3 miles of combined freeway/city to get started when I parked and let the EGT's cool below 400. :eek:

It will be interesting to see how many of those trips it will take to complete. Don't plan on driving the beast this weekend, so I expect it will still be waiting to complete the regen Monday unless somehow it completes it in the next 3 commute warm-ups tonight and Friday morning and night. ;)

Edit:
Found an errand to run 20 miles mostly freeway - that easily finished the regen started this morning. Interestingly when I parked it soot was 22 - when I went out 5 hours later soot level was 14....... What does it do keep cooking after you park. :)

DIC MPG read 14.0 when started and 13.8 when complete - fuel gage hardly moved.

I think it would have been able to regen in 2 days commuting if it drops that fast.

The regeneration process relies on a flow of oxides of nitrogen (produced by the Diesel Oxygen Catalyst) (DOC)) combined with a lot of heat, to oxidize the carbon deposits (soot) and other captured particulate matter in the Diesel Particulate Filter (DPF). At highway speeds, with a trailer on the back, the exhaust gasses are usually hot enough for somewhat continuous regeneration to occur. If not, and at lower speeds and loads, when the soot level reaches a predetermined point, a complex injection of additional fuel occurs (not in the power stroke) to increase the temperature of the exhaust gasses. This in turn gets the DOC and DPF doing their job of regeneration. Get an LMM, they are spectacular !!!

I never noticed any Regen in any form during the entire 4,000 trip. I can be dense at times, I assumed that the DIC would let me know the truck was in regen mode yet that seems to not be the case.
It makes sense that if the exhaust is hot enough, it could constantly clean itself.
The Chevy salesman told me the LMM does not regen while towing because the exhaust would be too hot and might damage the towed trailer. From the posts, that doesn't seem to be the case either.

Your salesman is not very well informed.

Firstly, the end of the tailpipe on the LMM is a venturi design, so that it sucks cold air in to the pipe to mix with the hot exhaust about 2 ft before the end of the pipe. This prevents the exhaust, during regeneration, from leaving the tailpipe at a temperature which would cause problems for anyone directly behind the pipe, or for your trailer.

Secondly, if the soot load in the DPF has reached the predermined level for regeneration to start, having a trailer on the back is not going to convince the on board computer to delay regeneration. When you've got to go, you've got to go !!!

Invite your salesman to become a member of this forum.

Hot Rod, another clue is a slightly increased idle RPM during regen. Mine jumps about 100-125 RPM when the regen occurs. Also, you may notice a significantly stronger diesel exhaust odor when it's happening, especially sitting at a stoplight or something. As stated above, it usually lasts 20-30 minutes if you are driving at or above 30 MPH or so. Below that, it may take a while to complete. The computer starts and stops it as you start and stop the truck. I've heard putting it into or out of park triggers it to suspend the regen if you stop the truck. It's all based on backpressure readings upstream and downstream of the DPF. As it clogs with soot, backpressure increases. At some predetermined backpressure threshold, it starts a regen to clean out the accumulated carbon. If you have recently reset your DIC mileage, you may notice a drop, as you are now using more fuel per mile, which has a big impact if you've only got 50-60 miles since the reset. If the mileage calculation is based on several tanks' worth, you won't notice a change because the temporary increase in fuel consumption is averaged out over a lot more miles. Welcome to Big Brother running your new diesel engine...