:)I hope this thread is of some help about the regens. The info here is what I have experience. Other trucks may vary. Mr.MOD. If you want to make this thread a sticky then do so.
mileage - miles between - soot mass
424 424 28.8
785 363 18.6
1148 385 18.2
1533 340 22.2
1877 364 32.4
2237 355 34.2
2592 347 22.6
2939 387 28.7
3326 365 28.2
3691 337 28.4
4028 358 28.8
4386 368 23.9
4754 411 23.4
5165 370 24.4
5535 415 24.2
5950 413 35.0
6363 386 35.1
6749 396 42.4

In traffic,the engine gets quieter but the rpm goes to 810. Interstate driving you dont tell a difference. The emg on the DIC does not change. The regen last between 10 to 18 miles +-.
All regens here are short trips except # 1,17 18 19 20 which are interstate driving.
When your egts are say around 1100 to 1200 and your soot is say 18 and you are really cooking and you cut the engine off for say 15 to 30 minutes and restart and go the soot will drop to maybe 10. I have tried every way I know to mess the cycle up by cutting the engine off and on several times and it done its thing anyway.
I have ask on DP several times how much soot mass it would take to trigger the clean exhaust filter light and never got a answer.
I dont like the regen cycle anymore than most people do.Its expensive. It stinks. Something else to mess up.I do think GM done the best they could with what they had to work with. In stock form I dont think it is going to be a problem other than a ECM problem. Believe me it is going to regen.
YES I would buy it again in a heartbeat. Its goodlooking, powerful. and drives like a dream. LOVE IT. :)

Good post, Thanks. Althought I don't have Dashhawk, so can't comment on the soot mass, your regen frequency is similar to mine. I think soot mass is only one of several parameters used to initiate a regen; mileage and load history probably are factored in as well. How much did you pay for the Dashhawk?

Good post, Thanks. Althought I don't have Dashhawk, so can't comment on the soot mass, your regen frequency is similar to mine. I think soot mass is only one of several parameters used to initiate a regen; mileage and load history probably are factored in as well. How much did you pay for the Dashhawk?
I paid $ 300.00 at the local Rino bed liner dealer who sells MSD ignition parts.

I paid $ 300.00 at the local Rino bed liner dealer who sells MSD ignition parts.

Ok, me dummy on this one. What is a dashhawk?

digital gauges. same thing as the edge insight

18 regens in 6749 miles, ever think about DPF delete

If on average your truck regens at 375 miles, you drive 100,000,000 that's 266.66 times it will Regen.

What do you think that cost of fuel and wear an tear on your truck is

266.66 x ?

Thanks for the info...I've been keeping track of my regens, and it averages around every 415 miles. I used to have the dashhawk hooked up but now have something else in place and I'm going to quit keeping track of regens soon, if you get my meaning... ;)

-Ronnie

18 regens in 6749 miles, ever think about DPF delete

If on average your truck regens at 375 miles, you drive 100,000,000 that's 266.66 times it will Regen.

What do you think that cost of fuel and wear an tear on your truck is

266.66 x ?
Dpf delete = no waranty. Believe me that is the only reason
:lol2::lol2::lol2::lol2::lol2:

>.... you drive 100,000,000 .....

100 million miles - Now that's Duramax durability!

Coming off the pass last night after a 400 mile day trip at 75mph+ mine went into regen with only 5 gallons left. Was going to try to get home without filling up, but after the fuel jettison finished I decided to fuel up. Took 22 gals at the pumps and 2 gals burned from there to get home. So would have had only 2 gals left maybe had I pushed it........

:eek:

That's 18MPG for the trip (400/22).. no better than before I switched to Mobil 1 engine oil before the trip. But darn good given the speed and 25 miles of city driving included and that regen included. Stock really ain't that bad MPG wise for me.......

:)

took a trip today 72.3 miles with a few hills and a lot of stop and goes. The DIC said I used 3.7 gallons. 19.54 ain't too bad for mileage, and the DIC seems within .2 or .3 mpg every time ive calculated it. Went through a regen on the trip and mileage dropped to 12.5 for a short period of time.

took a trip today 72.3 miles with a few hills and a lot of stop and goes. The DIC said I used 3.7 gallons. 19.54 ain't too bad for mileage, and the DIC seems within .2 or .3 mpg every time ive calculated it. Went through a regen on the trip and mileage dropped to 12.5 for a short period of time.
:)My mpg on the DIC has never went up or down while in regen and I watch it like a bad woman.:)

:)My mpg on the DIC has never went up or down while in regen and I watch it like a bad woman.:)

If your dic has been averaging your MPG is over a long distance, it might not show up as a big drop. Next time you go on a long trip (400 mi or so) reset the mpg first. You can also reset it during regen for a real shock.:eek:

Exactly I have only caught mine in regen twice in 15K miles. I happened to reset it once when the truck was pretty new cruising at 65 expecting to see 22mpg and it read 12mpg......

Last weekend as described in my previous post above I was watching the fuel used like a hawk and it really started to jettison. Switched to MPG and reset - sure enough 12mpg regen a happening.......

Changed the fuel filter first time tonight at 15K miles and 35% life remaining - took longer to get the fender liner out and in than the filter - easy cheesy. I even like the smell of diesel fuel.....

Without any aftermarket gauges, how do you know when your truck is in the regen cycle. This is my first diesel I have ever owned, 08 Silverado (LMM) I believe.

In regen, the truck will feel a little sluggish, may be slightly louder rattle when you lightly press the pedal.
Hit your trip reset and you will be averaging about 12 mpg when on highway unloaded. After about 20-30 min, the engine will sound better and mpg will start to climb and your gas gauge will not be falling as fast :D

Exactly I have only caught mine in regen twice in 15K miles. I happened to reset it once when the truck was pretty new cruising at 65 expecting to see 22mpg and it read 12mpg......

Last weekend as described in my previous post above I was watching the fuel used like a hawk and it really started to jettison. Switched to MPG and reset - sure enough 12mpg regen a happening.......

Changed the fuel filter first time tonight at 15K miles and 35% life remaining - took longer to get the fender liner out and in than the filter - easy cheesy. I even like the smell of diesel fuel.....


Same here. On a 400 mi trip last week, at 65 mph, 12 mpg during regen (for about 20 miles) and 21 mpg without regen.

Well, I have to say I do not miss the regen crap. I could only squeeze 14.7 mpg out of mine with the dpf delete. With dpf was about 13.9 mpg on the highway. Truck went into regen every 250 to 300 miles. That sucked literally. Probably due to the lift and tires.

Im suprised at the soot gram level when regen for you. Mine regens at 45 grams and does it for 1/2 hour or more at times. Doing dpf delete soon...parts on order. We will see how it goes. I have 40k on truck and I think regens have cost me 250-350 dollars if it only uses 1 gal of fuel. I know it uses more in my truck.

In regen, the truck will feel a little sluggish, may be slightly louder rattle when you lightly press the pedal.
Hit your trip reset and you will be averaging about 12 mpg when on highway unloaded. After about 20-30 min, the engine will sound better and mpg will start to climb and your gas gauge will not be falling as fast :D

Page 2-14 of the 08 Duramax manual states that a DIC message "Clean Exhaust Filter" will be displayed and that we are then to drive above 30mph for 20 miles. However, no message has EVER appeared on my Sierra. I've got 5000 miles on it now. I *think* the DPF regen is being conducted when I start to smell the vehicle run very rich - however there is no message so I don't know to head for the hiway or to go ahead and stop at the mall :).

Additionally my fuel economy has been pathetic. 13.3 mpg calculated by hand, all highway. I just bought the truck in September and was surprised when I looked at the factory build information - this truck has been sitting on a dealer's lot since Oct of 08. When it was delivered to me it had 500 miles on it. I'm beginning to wonder if it had sat on the lot for almost a year for a reason.

Any suggestions for increasing fuel economy?
Anyone else experiencing the complete lack of a DIC message when the DFP is cleaning?
Could my fuel filter be gummy from sitting for a year?
Any service bulletins/firmware flash/whatever that I should have the service department do to help increase the fuel economy?

I'm thrilled with the way this truck tows and stops (I haul horses and the integrated brake controller has been breaking great especially with the allison tow mode to help with the engine compression braking... however at this mileage I'm better driving my 01 Dodge Cummins that gets 20 mpg even after the ULSD and the People's Republic of California's fuel formulations. (The Dodge does have a Van Aakens 60hp chip.) It's a sweet, smooth haul if the mileage issues can be resolved.

:lol:

The clean DPF code is if you are not driving it in such a way that it can regen. Have never seen it in 15K since I do drive mine above 30mph.

:D

:lol:

The clean DPF code is if you are not driving it in such a way that it can regen. Have never seen it in 15K since I do drive mine above 30mph.

:D

It is called passive regeneration, where regeneration occurs under normal driving conditions, due to higher EGTS.;)

The "clean exhaust filter" warning is a last resort if your DPF is in a loaded condition and it does not sense enough speed. If it senses it is warm enough and enough speed it will go into regen, there is no stock indicator that a regen is taking place. Thus you may start a cycle but not know it or be able to complete one before your trip ends or you move to slower traffic. Then it really works hard when you restart the next time cold still in a regen cycle.


SilverGriff,
I assume you meant Oct 07 build? If that is the case, I would definately get an oil change and fuel filter change in NOW. That old fuel can not have been good on it at first.
You might also look at treating a few tanks with biocide to knock down anything that might have started to grow over that time. I have found running an additive to be helpful for both lubrication peace of mind and reducing smoke particulate which will corespond to reduced regens.
Welcome to life in the emmisions age :)

The "clean exhaust filter" warning is a last resort if your DPF is in a loaded condition and it does not sense enough speed. If it senses it is warm enough and enough speed it will go into regen, there is no stock indicator that a regen is taking place. Thus you may start a cycle but not know it or be able to complete one before your trip ends or you move to slower traffic. Then it really works hard when you restart the next time cold still in a regen cycle.


SilverGriff,
I assume you meant Oct 07 build? If that is the case, I would definately get an oil change and fuel filter change in NOW. That old fuel can not have been good on it at first.
You might also look at treating a few tanks with biocide to knock down anything that might have started to grow over that time. I have found running an additive to be helpful for both lubrication peace of mind and reducing smoke particulate which will corespond to reduced regens.
Welcome to life in the emmisions age :)

Yes, sorry '07 is the build date on the manufacturer paper work...typed '08 by habit.

Which diesel additive do you recommend? I've used the Howes Meaner Power Cleaner in my Dodge, but I must admit to feeling "bullied" by the manual for the GMC with all the breath-wrong-inside-your-truck-and-your-warranty-will-be-void language. Off topic, I also have a VW Jetta TDI '06 and have seen a decrease in its mileage with the advent of the ULSD and have wondered if I needed to start throwing in a lubricant additive in it as well.

Is there a different additive that would be the biocide?

Thank you all for your input!