New duramax vs new Cummins

[SteveSRT8]

Originally Posted By: horse123
So if tuning... no duramax? Unless it's planned to replace many more parts with the tune. Or is it just be careful with who you choose for a tune?


While many tuning shops have great expertise there are many who are simply button pushers making big money off truck enthusiasts.

Even the biggest companies selling aftermarket tunes do not have the incredibly expensive and diverse testing and dyno time the OEM's do. Not even close.

Frankly the "HUGE GAINS FOR NOTHING" promise of handheld tuners is quite naive because HP sells these vehicles. The OEM stops where they do because of warranty claims, period.

I have run a Diablsport tune on my 6.1 for many years without a hiccup, but I never jumped into the pond expecting something for nuttin'.

My 09 Dmax is completely stock OE, and will stay that way. When I want to race I'll start with a different platform, not a pickup truck...

 

[440Magnum]

Originally Posted By: horse123
So if tuning... no duramax? Unless it's planned to replace many more parts with the tune. Or is it just be careful with who you choose for a tune?


Well... everything the guys said about the Allison 1000 (clutch-to-clutch shifting, PCM torque management during shifts, etc.) happens in the 68RFE, too. "Tuning" is always a risk, because these days the software is SO integral to drivetrain performance that a mistake by the guy doing the tuning can literally break parts. In most cases the size and cooling capacity of modern transmission clutches is selected on the assumption that there will be torque management during shifts. Older analog automatics had oversized clutches just to absorb the (wasted, I might add) torque during the long greasy shifts that were needed to make shifting smooth. A modern auto with torque management can shift much faster because the torque management is doing the smoothing and the software doesn't have to slip the clutch so long (just listen to a Hellcat running through the gears WOT if you need convincing that torque management can be used to advantage). Win-win from a performance perspective... but along comes a tuner who is convinced that old-style bang-shifting at full torque "gives better performance," eliminates torque management in a tune, and breaks stuff for virtually no performance gain.

I would say, "use a tuner at your own risk" in all cases, but the potential breakage with diesels is probably bigger simply because a) you can "tune" in so much more torque, and b) the torque is already big.

 

[horse123]

One other question about modern diesel trucks. How problematic is EGR actually? You see all these ugly pictures of completely soot blocked engine parts, and people act like it's cancer. But I thought there was some cycle the ECU or whatever controls EGR goes through that burns that off using a little extra fuel every so often. What's the deal there?

 

[TiredTrucker]

That is after the EGR has already made the engine eat its own feces. The biggest issue with EGR is EGR coolers. When one of them goes, there is a very high risk of engine coolant being fed direct to the cylinders. I am truly surprised, with the advent of SCR systems on diesels now, that EGR has not been totally eliminated. I see no reasoning for keeping it on a diesel now. The SCR can take care of the NOx. The DPF would also last longer, as there would be less soot loading of it that it has to capture and burn off. Even if it required a lot more DEF use by the SCR to handle the added NOx by not having EGR, it would be more cost effective in the long run.

 

[clinebarger]

Originally Posted By: horse123
One other question about modern diesel trucks. How problematic is EGR actually? You see all these ugly pictures of completely soot blocked engine parts, and people act like it's cancer. But I thought there was some cycle the ECU or whatever controls EGR goes through that burns that off using a little extra fuel every so often. What's the deal there?


The exhaust "soot" mixes with oil vapor from the PCV system inside the intake tract...And forms some tar looking build up. No way for engine management to clean that.
I blocked my EGR a while back, And used Tuning Software to turn the codes off.
Had the intake/Y-bridge off not to long ago. It IS NOT as bad as the internet experts said it would be with over 200K with the EGR functioning. About 1/8" buildup in the intake. In my opinion the issue is overblown.


Sounds like your referring to a DPF regeneration cycle, Extra fuel is used to burn of soot that builds-up in the Filter.

The newer LML Duramax's have a 9th injector in the exhaust to supply fuel for a "Regen"

The Cummins & Powerstroke achieve this "In Cylinder", Some of that fuel ends up in the crankcase/oil.

I recommend test driving all the big 3 offerings for a weekend each, That's what I did in early '06.

 

[horse123]

Well I'll certainly drive the 2 I've mentioned in this thread

 

[TiredTrucker]

At least on the larger diesels, the OEM's have figured out that putting an oil catch / filtering system on their engines keeps the oily junk out of the intake and combining with the EGR soot. Would be nice if all diesels being made had some from of oil separation thing. Still, with the advent of SCR, EGR should be done away with. Should be an easy tune mod kind of thing that shuts it down. They are ECM controlled. Just turn it off. I did with my Jeep Liberty diesel with EGR.. Just tuned it to never operate. Never saw the oil so clean for so long after that move. Just leave the other downstream stuff left to do its thing like nothing out of whack.

 

[Clevy]

Originally Posted By: TiredTrucker
At least on the larger diesels, the OEM's have figured out that putting an oil catch / filtering system on their engines keeps the oily junk out of the intake and combining with the EGR soot. Would be nice if all diesels being made had some from of oil separation thing. Still, with the advent of SCR, EGR should be done away with. Should be an easy tune mod kind of thing that shuts it down. They are ECM controlled. Just turn it off. I did with my Jeep Liberty diesel with EGR.. Just tuned it to never operate. Never saw the oil so clean for so long after that move. Just leave the other downstream stuff left to do its thing like nothing out of whack.


Though I agree with the sentiment I don't think adjusting out an engineered component on a new engine is in a new owners best interest while still under factory warranty.
Diesels in passenger cars are a new thing on this side of the pond. Many aren't familar with exactly how these engines work and that ignorance can potentially put an owner on the hook if for any reason there is a failure.
Once they become more mainstream and the tuner crowd starts modding various platforms beyond designed capabilities then we will see exactly what can be removed,and what has to stay to retain reliability and longevity.
Give it a decade or so and there will be lots of info,and real wallet,I mean world experience,as well as umpteen millions of miles of beta testing by consumers,and aftermarket companies which will add a comfort level for owners,as well as data so the consumer can make an informed choice.
You've got millions of miles behind a diesel,let the rest of the continent catch up.

 

[Jarlaxle]

Originally Posted By: horse123
One other question about modern diesel trucks. How problematic is EGR actually? You see all these ugly pictures of completely soot blocked engine parts, and people act like it's cancer. But I thought there was some cycle the ECU or whatever controls EGR goes through that burns that off using a little extra fuel every so often. What's the deal there?


EGR in a diesel sucks rocks. No exceptions.

Honestly...new diesels have gotten so finicky, fragile, and complicated that I would not own one. After 2007, go gas.

 

[hattaresguy]

Originally Posted By: jeepman3071
With the high price tag of a diesel truck ($70-80k) I wouldn't tune it at all. Tuning voids the warranty and I don't see those tuning companies offering engine/transmission warranties for your vehicle.

My friend has a Duramax with EFI live. I just helped him do his 5th Allison tranny swap a few months ago (which in my opinion is insane and a huge waste of money). Thankfully this one has been built by Alligator performance so it can handle the power, but adding lots of performance tuning to any diesel pickup is just asking for repair bills. With the exception of the very light tunes and custom tunes some of them are very bad for your engine and trans. Don't even get me started on the EGR and DPF systems with tuning. I've seen people melt their entire engine after one romp down the highway. Some of the tuners such as the H&S tuners advance the timing in the engine way too much, and with the additional fuel it is only a matter of time before it melts a piston.

My friend took a fairly bullet proof combo of the Duramax/Allison and made it a complete money pit from all the tuning he has done. His brother has a completely stock and well maintained 6.0 powerstroke which is almost to 200k miles with nothing but regular maintenance and coolant changes. These new diesels get very expensive very quickly, and if I bought one it would stay stock for a LONG time. The only things I would add would be a coolant filter and a fuel additive for the injectors to help lubricate them.


I don't get this part of the big diesel truck crowed at all. If I drop big money on a diesel rig I expect it to be like a commercial truck, ie 200k-300k miles with no drama. I don't care about speed, if you want speed buy a Corvette.

IMHO the entire point of spending big bucks on the diesel and heavy duty transmission is so you can do truck stuff for a long time and not break stuff. IE like my framer who pulls a Lull with his F350 and is quickly coming up on 300k miles.

 

[jeepman3071]

Originally Posted By: hattaresguy


I don't get this part of the big diesel truck crowed at all. If I drop big money on a diesel rig I expect it to be like a commercial truck, ie 200k-300k miles with no drama. I don't care about speed, if you want speed buy a Corvette.

IMHO the entire point of spending big bucks on the diesel and heavy duty transmission is so you can do truck stuff for a long time and not break stuff. IE like my framer who pulls a Lull with his F350 and is quickly coming up on 300k miles.



Yup, I agree completely. My buddy is pushing 800hp, has a huge lift, tires, exhaust, etc, and he doesn't even tow anything or use the bed. He specifically bought the 2500HD for its "heavier duty" qualities, and after all his mods it rides like a school bus. Not to mention between the modded transmission and all the torque it is TERRIBLE in the snow. All so he can commute just 10 miles to work. His dad tows a giant camper with a 14 year old 1500 Silverado.

 

[hattaresguy]

I don't get it, if I were going to blow stupid money on a vehicle to get me to work it would be an Audi S8 or Mercedes S550 4 Matic. At least they would be comfortable, nice driving cars, which are both excellent in the snow.

If I bought a 2500 I'd have a utility body and a plow mounted on it.

 

[xxch4osxx]

Originally Posted By: jeepman3071
Originally Posted By: hattaresguy


I don't get this part of the big diesel truck crowed at all. If I drop big money on a diesel rig I expect it to be like a commercial truck, ie 200k-300k miles with no drama. I don't care about speed, if you want speed buy a Corvette.

IMHO the entire point of spending big bucks on the diesel and heavy duty transmission is so you can do truck stuff for a long time and not break stuff. IE like my framer who pulls a Lull with his F350 and is quickly coming up on 300k miles.



Yup, I agree completely. My buddy is pushing 800hp, has a huge lift, tires, exhaust, etc, and he doesn't even tow anything or use the bed. He specifically bought the 2500HD for its "heavier duty" qualities, and after all his mods it rides like a school bus. Not to mention between the modded transmission and all the torque it is TERRIBLE in the snow. All so he can commute just 10 miles to work. His dad tows a giant camper with a 14 year old 1500 Silverado.
Where do these guys get the money to buy the truck new, then do all those mods to them and then keep them on the road after breaking driveline parts? Such a waste, in my opinion.

 

[Nate1979]

Originally Posted By: hattaresguy
I don't get it, if I were going to blow stupid money on a vehicle to get me to work it would be an Audi S8 or Mercedes S550 4 Matic. At least they would be comfortable, nice driving cars, which are both excellent in the snow.

If I bought a 2500 I'd have a utility body and a plow mounted on it.


Can you roll coal in those cars though? J/k

 

[440Magnum]

Originally Posted By: TiredTrucker
I am truly surprised, with the advent of SCR systems on diesels now, that EGR has not been totally eliminated. I see no reasoning for keeping it on a diesel now. The SCR can take care of the NOx. The DPF would also last longer, as there would be less soot loading of it that it has to capture and burn off. Even if it required a lot more DEF use by the SCR to handle the added NOx by not having EGR, it would be more cost effective in the long run.



All the jokes about "pee tanks" aside, SCR does make a lot of sense. It works so well with the DPF its hard to believe that some of the manufacturers tried to live with EGR alone. SCR lets the engine run very oxygen-rich so that it doesn't make a lot of soot in the first place, cleans up the NOx from running lean, and that frees up MORE oxygen for the reduction catalysts and to continually burn the soot on the DPF, even when not in "regenration" mode provided the engine's working hard enough to get the DPF hot.

That last sentence is the biggest problem with pickup truck diesels. Most of them never work hard enough to really keep the DPF clean, and the problems cascade backward from there.

If I needed a 1-ton truck occasionally but knew I wasn't going to tow hard with it day in and day out, I'd get a Ram 3500 with the 392 gasser. Yeah, gas mileage will suck... but the total life-cycle cost of a gasser wins big-time (especially with diesel more expensive than gasoline!) when the duty cycle is light or infrequent.

 

[RISUPERCREWMAN]

Originally Posted By: xxch4osxx
Originally Posted By: jeepman3071
Originally Posted By: hattaresguy


I don't get this part of the big diesel truck crowed at all. If I drop big money on a diesel rig I expect it to be like a commercial truck, ie 200k-300k miles with no drama. I don't care about speed, if you want speed buy a Corvette.

IMHO the entire point of spending big bucks on the diesel and heavy duty transmission is so you can do truck stuff for a long time and not break stuff. IE like my framer who pulls a Lull with his F350 and is quickly coming up on 300k miles.



Yup, I agree completely. My buddy is pushing 800hp, has a huge lift, tires, exhaust, etc, and he doesn't even tow anything or use the bed. He specifically bought the 2500HD for its "heavier duty" qualities, and after all his mods it rides like a school bus. Not to mention between the modded transmission and all the torque it is TERRIBLE in the snow. All so he can commute just 10 miles to work. His dad tows a giant camper with a 14 year old 1500 Silverado.
Where do these guys get the money to buy the truck new, then do all those mods to them and then keep them on the road after breaking driveline parts? Such a waste, in my opinion.


I agree totally! Who drops 60K on a new diesel rig & molests it by ripping it apart & voiding the factory Warranty? A fool & his money are parted every day! LOL

 

[SteveSRT8]

Originally Posted By: 440Magnum
...provided the engine's working hard enough to get the DPF hot.

That last sentence is the biggest problem with pickup truck diesels. Most of them never work hard enough to really keep the DPF clean, and the problems cascade backward from there.

If I needed a 1-ton truck occasionally but knew I wasn't going to tow hard with it day in and day out, I'd get a Ram 3500 with the 392 gasser. Yeah, gas mileage will suck... but the total life-cycle cost of a gasser wins big-time (especially with diesel more expensive than gasoline!) when the duty cycle is light or infrequent.


You said the real thing here: How hard is it worked?

Very few folks have many problems if the diesel works a bit, they need some load to generate the heat and flow needed. Many of the folks I hear of with problems are just joy riding them, driving them to work and such...

 

[TiredTrucker]

Originally Posted By: 440Magnum

If I needed a 1-ton truck occasionally but knew I wasn't going to tow hard with it day in and day out, I'd get a Ram 3500 with the 392 gasser. Yeah, gas mileage will suck... but the total life-cycle cost of a gasser wins big-time (especially with diesel more expensive than gasoline!) when the duty cycle is light or infrequent.


Well diesel being more expensive than gas, for the general public, that is true. I just filled my semi truck in Lasalle, IL at the Flying J tonight. Pump price was $3.16. I got $1.30 discount, at the pump, when I fueled. My cost for the fill up was $1.86 a gallon. I filled the night before there and got $1.18 a gallon discount. Nope, no grocery store discount card kind of thing. This has been typical of discounts I have been getting commercially since fuel prices started heading into the basement. For the last 3 weeks, my average cost for diesel has been roughly $2.03 a gallon. And I typically fill 100+ gallons at a time. I go thru just under 20,000 gallons of diesel a year.

Wanted to put that out there for perspective. The fuel is not anywhere near the cost that the average consumer is paying. Commercial accounts are getting royal discounts on diesel. The average consumer is getting nailed. This ought to raise some eyebrows.

And I used the governments own rules against them when I ordered up the 2013 semi truck I have now. I ordered it without an engine or transmission. Complete truck other than that. Then I dropped in a factory remanned pre-egr Detroit 60 in it, along with a factory remanned 18 speed Eaton. The OEM knew what I was going to do, and provided all the wiring harnesses and other goodies to match up my engine to the truck. No emissions stuff of any kind. Dig into the details at the EPA, and you find they tie the emissions standards to the year the engine is made and not the vehicle itself. One of those little hidden "loopholes" that didn't get plugged. My semi is titled and registered as a 2013 truck.

 

[Fordtrucktexan]

Originally Posted By: TiredTrucker
Originally Posted By: 440Magnum

If I needed a 1-ton truck occasionally but knew I wasn't going to tow hard with it day in and day out, I'd get a Ram 3500 with the 392 gasser. Yeah, gas mileage will suck... but the total life-cycle cost of a gasser wins big-time (especially with diesel more expensive than gasoline!) when the duty cycle is light or infrequent.


Well diesel being more expensive than gas, for the general public, that is true. I just filled my semi truck in Lasalle, IL at the Flying J tonight. Pump price was $3.16. I got $1.30 discount, at the pump, when I fueled. My cost for the fill up was $1.86 a gallon. I filled the night before there and got $1.18 a gallon discount. Nope, no grocery store discount card kind of thing. This has been typical of discounts I have been getting commercially since fuel prices started heading into the basement. For the last 3 weeks, my average cost for diesel has been roughly $2.03 a gallon. And I typically fill 100+ gallons at a time. I go thru just under 20,000 gallons of diesel a year.

Wanted to put that out there for perspective. The fuel is not anywhere near the cost that the average consumer is paying. Commercial accounts are getting royal discounts on diesel. The average consumer is getting nailed. This ought to raise some eyebrows.

And I used the governments own rules against them when I ordered up the 2013 semi truck I have now. I ordered it without an engine or transmission. Complete truck other than that. Then I dropped in a factory remanned pre-egr Detroit 60 in it, along with a factory remanned 18 speed Eaton. The OEM knew what I was going to do, and provided all the wiring harnesses and other goodies to match up my engine to the truck. No emissions stuff of any kind. Dig into the details at the EPA, and you find they tie the emissions standards to the year the engine is made and not the vehicle itself. One of those little hidden "loopholes" that didn't get plugged. My semi is titled and registered as a 2013 truck.


That's one of the most interesting things I've heard. Is this exclusive to class 8 rigs, or all diesel trucks? On my F250, I'm completely emissions deleted and now they're emissions testing in Houston, about 90 miles from me.

You're right about 'average' diesel consumers getting screwed. I paid $2.94/gal today but the little bit I put in will probably last two weeks since this truck is far from a daily driver. Lately I've just been driving it just to get fluids up to temp and keep it from sitting - one of the worst things you can do to a diesel.

 

[TiredTrucker]

It is only an exclusive to the class 8 trucks because only the class 8 OEM's offer to do it. Any auto or pickup OEM could do the very same thing, offer a chassis and body thru the parts stream and then the end user could install the power train themselves. But, no consumer auto/pickup OEM offers this because of their limited vision and lack of knowledge. Heck, depending on state regulatory issues, anyone can build a car or pickup from scratch and install the power train of their choice, have it titled and registered as a new model year. It would only have to meet DOT on road requirements for occupant safety, lighting, brakes, etc of current model vehicles. That is basically the concept of getting a full truck chassis and body from a heavy truck OEM and dropping in the power train later. It is basically a "kit" truck, that is the same as if you built a kit vehicle in your garage. Just that the OEM is assembling the "kit" for you. It is just that simple.

I did a check one day of the requirements of my state to basically build a kit car, for on road use, from scratch. Not a problem. Just has to meet DOT requirements for use on road. So, that idea, along with an OEM that has the foresight to play in the same sandbox, and I have a factory assembled "kit" truck with a pre-emissions engine in it. I saved $40,000 over the cost of a brand new production truck spec'd similarly, and my operation costs are lower since I do not have to deal with all the emissions stuff on it. And reciprocity between states allows me to run this same truck multi state and do everything that a regular full production truck hauling freight can do. California is the only fly in the ointment, so to speak, in that they have decided to become their own EPA regulatory body and restrict commercial vehicles that do not meet certain emissions guidelines. That's ok. I haven't hauled anything in or out of California since the last century, with no desire to do so ever again.

Man, what a country! And I am not in a minority doing this with a truck. There are thousands of these "kit" trucks running around the country. My dealer alone is putting together almost 2000 of these kit trucks for buyers every year. And there are several other dealers and outlets doing this for buyers around the country. The truck comes in from the factory, the dealer drops in the engine and transmission of the user's choice, and a completed truck is ready to go to work. There are even entire carrier fleets that are comprised only of pre-emission kit trucks!