'24 AT4X 3.0 Duramax or '24 F150 Tremor 3.5 EB

[yammahaw]

So I have a burning question which I have read so much on that I am truly torn. Many forms out there seems to bash the purchasing of a diesel if you are not going to "tax" it. Stating things such as they are meant to be ran hard and they are not meant to be daily short trip drivers etc. While I fully believe that for HD trucks and trucks 10 years ago, I find it hard to believe that newer trucks with newer technology don't have a way to make this a reality.

Nonetheless, my burning question comes from a place of MPG and overall usability/longevity. I live in Wyoming where the weather can go from -'s F to +'s F in a blink of an eye. My driving averages about 8K a year (due to annual hunting trips (100-200 miles round trip). I do not have anything to tow and utilize the truck to haul things like lumber, dogs, grass and the family. I take trips down to Colorado (90 miles round trip) every once in a while, but the trips are not on a consistent basis. Travel on the daily would be 5-20 miles round trip with speeds around 40. I am torn on which truck to go with due to similar costs and functionality. As state above the forms I have read and individuals I have spoken with have given me concerns which I cannot seem to shake. Hopefully you all can help provide some clarity and guidance

Concerns:
Regens- I do not travel far and long at any given time, I worry about about the DPF filter getting clogged and the truck going into limp mode.
DEF - I worry about the truck utilizing too much DEF which would increase the overall maintenance costs.
Maintenance - Cost seems to be more than a gas truck and seems there is more to do than what I am aware.
Daily driving costs - Currently the cost between regular and diesel is .30 per gallon, however if I have to drive for an hour to get the truck to regen, is it worth it?
Cold startups - I've been told that these trucks are hard to start in the cold, but should not be plugged in unless its colder than -12F, any truth to that?
Wear and tear - With the requirement to burn off and do a Regen, how much more wear and tear will this cause to my truck?

I am sure there are more and I would love to hear everyone's thoughts on this. I am really leaning towards the Duramax, but want to make sure I am not making a 75K mistake.

 

[chaseydog]

I've got about 6500 miles on a 24 AT4 3.0L. My daily drive is 6 miles each way to work, plus some additional miles running errands. On weekends I'll usually put another 50 - 100 miles on the truck doing longer runs. No towing.

A regen typically takes me 10 - 12 miles at 35 - 45 mph. I'm hitting a regen every 180 miles or so. DEF usage has been light, I added 2.5 gallons at around 3500 miles and will be adding another 2.5 soon.

I live in NC so cannot answer your cold wether questions. I've been very happy with the diesel and have no concerns with short runs not being the optimal way to run a diesel. The way I see it there are a lot of passenger cars in Europe with 1L to 2L diesels, and the 3L in my truck is closer to that displacement than the 6.6 in the HD.

 

[yammahaw]

@NMTRUCKER Most of the time my drives will be more around the 10 mile round trip with the occasional one being more than that. I usually like to remote start my truck and let it warm up /cool down dependent on the weather. I am not opposed to going with the 3.5EB but IMO spending equal to or more for a 3.5 over a Duramax seems silly. In looking at the MPG difference its marginal, but the 3.0 still gets better. Also I did watch some other videos where the guy compared the 3.0 to the 5.3 and the 6.2 and the 3.0 still came out ahead in being less expensive.
I guess I would ask if you honestly think that driving a short distance repeatedly on this engine is any different than driving a short distance on the 6.2?

@chaseydog Do you have any regrets on the purchase? Did you look at the EcoBoost at all? What was the deciding factor for you on pulling the trigger?

Additionally to everyone, has there been any concerns about sensors going out or having to take it to the shop for DPF/cat being clogged ?

 

[chaseydog]

@chaseydog Do you have any regrets on the purchase? Did you look at the EcoBoost at all? What was the deciding factor for you on pulling the trigger?

I started off looking at Colorado/Canyon but moved on to the 1500 when I decided a full size truck was a better option for me. By that time the GMC look had won me over and the choice was between the AT4 and the Denali. The AT4 won that battle so the choice at that point was the 3.0L or the 6.2L.

Why pick the diesel over the big gasser? I wasn't looking for muscle car performance and the mpg of the diesel is more important to me. Base price is a bit lower and most of the AT4 dealer stock near me was 3.0L. But the real reason, if I'm being honest, is I've never owned a diesel before, but it was on my bucket list of things I wanted to do.

No regrets.

 

[yammahaw]

I've got about 6500 miles on a 24 AT4 3.0L. My daily drive is 6 miles each way to work, plus some additional miles running errands. On weekends I'll usually put another 50 - 100 miles on the truck doing longer runs. No towing.

A regen typically takes me 10 - 12 miles at 35 - 45 mph. I'm hitting a regen every 180 miles or so. DEF usage has been light, I added 2.5 gallons at around 3500 miles and will be adding another 2.5 soon.

I live in NC so cannot answer your cold wether questions. I've been very happy with the diesel and have no concerns with short runs not being the optimal way to run a diesel. The way I see it there are a lot of passenger cars in Europe with 1L to 2L diesels, and the 3L in my truck is closer to that displacement than the 6.6 in the HD.

Have you had any issues with the emissions as of yet? I am still leaning on going this route; however, I am curious to know about any other nuisances that I may have missed.

 

[yammahaw]

Driving a diesel consistently for short distances is worse than with a gas motor. Why? At highway speeds your exhaust gas temperatures are going to be 800-900 degrees F. or higher. Consequently, at these EGTs the DPF is undergoing what’s known as a passive REGEN where some of the soot is being burned off. Hence longer distances between REGENS. During short distance commuting at city speeds the EGT is probably going to be 500-600 degrees F. At those temperatures all the soot is going into the DPF and no passive regeneration is taking place. Remember that during a REGEN not all of the soot is being burned off. A very small percentage remains in the DPF. Eventually the DPF becomes clogged and needs replacement. How long that takes is dependent upon how the truck is driven. The more REGENS performed the less the lifetime of the DPF. In Europe the automotive repair industry uses a chemical process to clean out the DPF. I don’t think those services are available in the US but I might be wrong.

I read that because the DPF is closer to the engine it does not take nearly as long to heat up to temp as the 6L Duramax, thus making regens faster and more sustainable with shorter drives. If one were to go this route with say 1 highway round trip (100 miles) would that change your recommendation?

 

[chaseydog]

Have you had any issues with the emissions as of yet? I am still leaning on going this route; however, I am curious to know about any other nuisances that I may have missed.

I did have a P2297 CEL at about 3000 miles. The CEL cleared itself later that day and I haven't had any CEL's since. I'm now at 6500 miles. At the time the dealer told me there was no TSB for that code. Since that time GM has released a TSB for the 24 LZO that covers a dozen or so emissions related codes.

 

[chaseydog]

At highway speeds your exhaust gas temperatures are going to be 800-900 degrees F. or higher. Consequently, at these EGTs the DPF is undergoing what’s known as a passive REGEN where some of the soot is being burned off. Hence longer distances between REGENS. During short distance commuting at city speeds the EGT is probably going to be 500-600 degrees F.

I went back a d looked at a snapshot I took of my iDash a while back when performing a city driving regen and I was hitting 722 degrees F on EGT1. I'll try data logging next time I get close to a regen.

Intersting about how they clean the DPF in Europe. I did not know that.

 

[chaseydog]

I hit a regen this afternoon and captured it on the Banks iDash. EGT1 Temps were in the 600 to 800 degree F range with a high of 827. This was city traffic with a couple runs where I could open the truck up to 45 -55 mph.

 

[yammahaw]

I hit a regen this afternoon and captured it on the Banks iDash. EGT1 Temps were in the 600 to 800 degree F range with a high of 827. This was city traffic with a couple runs where I could open the truck up to 45 -55 mph.

View attachment 534
View attachment 535

So I am assuming that the times on the bottom are in seconds and MS? If so it took you 43 minutes? I am not familiar with the iDash at all so you will have to help me out. Also, have you ever just ran the engine in manual and kept the RPM's up past 2500 to help with the temp increase?

 

[testerdahl]

So I am assuming that the times on the bottom are in seconds and MS? If so it took you 43 minutes? I am not familiar with the iDash at all so you will have to help me out. Also, have you ever just ran the engine in manual and kept the RPM's up past 2500 to help with the temp increase?

I ran the same iDash in my Silverado, however, I’m not into the data as much as others. I also never had an issue with regen and, frankly, I think it is an overblown concern for prospective diesel owners. It is almost like they talk themselves out of buying one because of regen. That’s really unfortunate.

Here is the product IF you hadn’t seen it: https://bankspower.com/collections/...uUYMx-Xj831RNCKs2BWVkIBWmH3rQgNhoCE2MQAvD_BwE

 

[yammahaw]

I ran the same iDash in my Silverado, however, I’m not into the data as much as others. I also never had an issue with regen and, frankly, I think it is an overblown concern for prospective diesel owners. It is almost like they talk themselves out of buying one because of regen. That’s really unfortunate.

Here is the product IF you hadn’t seen it: https://bankspower.com/collections/idash-digital-monitor?utm_term=&utm_campaign=FMDM+++iDash+Gauge+++P-Max+++Conversion&utm_source=adwords&utm_medium=ppc&hsa_acc=9571795920&hsa_cam=17290070138&hsa_grp=&hsa_ad=&hsa_src=x&hsa_tgt=&hsa_kw=&hsa_mt=&hsa_net=adwords&hsa_ver=3&gad_source=1&gclid=CjwKCAjw1emzBhB8EiwAHwZZxYlMWVXtTHCFQcOzONDGZduUYMx-Xj831RNCKs2BWVkIBWmH3rQgNhoCE2MQAvD_BwE

I think my over encompassing concern is causing damage to the truck by not "using" it, but again is that an old school mentality?

 

[testerdahl]

I think my over encompassing concern is causing damage to the truck by not "using" it, but again is that an old school mentality?

I can tell you with certainly that you hear a LOT of conflicting information owning a diesel. When I had the Silverado, I'd hear all sorts of different things.

For example:

Claim: You have to idle a diesel especially in the winter because they are hard to start.

False: idling a diesel is a much faster way to plug up the DPF than short trips. The diesel mechanics and engineers I talked with all said the same thing. Don't idle the diesel.

And new diesels start much better than old diesels. I remember having many a farmer stop by to ask "do you still have to plug them in?"

I was once with some diesel engineers at the I-80 truck stop and the younger ones were shocked to see diesels idling. They couldn't believe owners would knowingly do this to their trucks.

If you look at the owner's manual for for the Duramax diesel, it has 6 references to idling and how you should avoid it in most cases due to problems with regen.

Here's one section:

"Avoid extended idling because the DPF system is not capable of self-cleaning at idle. During extended idling, monitor the instrument cluster lights and DIC for messages and take appropriate action. Continued idling with the warning light/message on could cause damage to the DPF requiring repair and possible replacement that might not be covered by the vehicle warranty."

Claim: You have to add additives to diesel fuel since it doesn't come with any from the pump.

False: new diesel fuel comes with conditioners if you buy from a reputable gas station. You CAN add additives, but they aren't at all necessary as they used to be. Shell, for example, has been adding additives to their fuel for some time.

Claim: Short trips cause major issues with diesels.

False: short trips don't cause major issues and IF the truck goes into regen, it will tell you to keep driving it until regen is complete. The newer diesels can also do a start and stop regen if needed. What I mean is if you turn the truck off, it can restart the regen process.

Here is a video from GM talking about short trips:

Also, if you are interested in how much diesels have changed, I talked with a Ford diesel engineer who has worked on them since the 1980s IIRC. Its been a while since I watched this interview:

IMO - diesel is superior to gas for torque, fuel economy and can be a lot better at towing in HD trucks. Americans just have images of black smoke, raw fuel smell and the extra maintenance concerns that hinder it from being a more popular option.

 

[yammahaw]

I can tell you with certainly that you hear a LOT of conflicting information owning a diesel. When I had the Silverado, I'd hear all sorts of different things.

For example:

Claim: You have to idle a diesel especially in the winter because they are hard to start.

False: idling a diesel is a much faster way to plug up the DPF than short trips. The diesel mechanics and engineers I talked with all said the same thing. Don't idle the diesel.

And new diesels start much better than old diesels. I remember having many a farmer stop by to ask "do you still have to plug them in?"

I was once with some diesel engineers at the I-80 truck stop and the younger ones were shocked to see diesels idling. They couldn't believe owners would knowingly do this to their trucks.

If you look at the owner's manual for for the Duramax diesel, it has 6 references to idling and how you should avoid it in most cases due to problems with regen.

Here's one section:

"Avoid extended idling because the DPF system is not capable of self-cleaning at idle. During extended idling, monitor the instrument cluster lights and DIC for messages and take appropriate action. Continued idling with the warning light/message on could cause damage to the DPF requiring repair and possible replacement that might not be covered by the vehicle warranty."

Claim: You have to add additives to diesel fuel since it doesn't come with any from the pump.

False: new diesel fuel comes with conditioners if you buy from a reputable gas station. You CAN add additives, but they aren't at all necessary as they used to be. Shell, for example, has been adding additives to their fuel for some time.

Claim: Short trips cause major issues with diesels.

False: short trips don't cause major issues and IF the truck goes into regen, it will tell you to keep driving it until regen is complete. The newer diesels can also do a start and stop regen if needed. What I mean is if you turn the truck off, it can restart the regen process.

Here is a video from GM talking about short trips:

Also, if you are interested in how much diesels have changed, I talked with a Ford diesel engineer who has worked on them since the 1980s IIRC. Its been a while since I watched this interview:

IMO - diesel is superior to gas for torque, fuel economy and can be a lot better at towing in HD trucks. Americans just have images of black smoke, raw fuel smell and the extra maintenance concerns that hinder it from being a more popular option.

I think what you are saying is matching up exactly with what I believe. A lot of people are stuck on the old school mentality and forget that things evolve.

Did you happen to read this article (https://www.motortrend.com/features...20-silverados-new-3-0l-duramax-6-turbodiesel/) and can you shed any light to the new EGR/SCR system?

 

[chaseydog]

So I am assuming that the times on the bottom are in seconds and MS? If so it took you 43 minutes? I am not familiar with the iDash at all so you will have to help me out. Also, have you ever just ran the engine in manual and kept the RPM's up past 2500 to help with the temp increase?

The bottom graph depicts the regen trigger, with a value of 1 meaning regen is off and a value of 3 meaning the regen is active. The regen runs from 786 to 1571 seconds, or just over 13 minutes.

I've never had a need to try running a standing regen. As far as I know thats an option on fleet vehicles but not on personal vehicles. The only concession I make to regen is that once I starts I try to complete the run without shutting down. Strictly speaking thats not necessary. Tbe truck will pick back up on the regen next time you drive. As long as you dont continue to short the regen it shouldn't be a problem from what I can tell.

 

[yammahaw]

I really appreciate everyone's input on this matter. It is very helpful. I did find this other form which attests to what people have said here that as long as you don't short the regens, you will be fine. (

https://www.reddit.com/r/gmcsierra/comments/1al7txk

).

Another question I have is pertaining to maintenance costs. I currently own a Tundra and my maintenance costs are around $75-$90 for an oil change, inspection fluid top off and tire rotation. I do this at the standard 5k miles.
What would you recommend on the Duramax?
What are the cost everyone pays from the dealer?
What are the standard DIY costs?
What else are you including in your maintenance and what is that cost?

 

[chaseydog]

My cost for the oil change I did myself was about $65 for ACDelco DexosD 0w-20 and a PF-66 filter. I'll be doing all my own aervice work. I'm planning on 5k intervals for oil and tire rotation and 10k for fuel filter and air filter.

 

[testerdahl]

I think what you are saying is matching up exactly with what I believe. A lot of people are stuck on the old school mentality and forget that things evolve.

Did you happen to read this article (https://www.motortrend.com/features...20-silverados-new-3-0l-duramax-6-turbodiesel/) and can you shed any light to the new EGR/SCR system?

I swear I forget more than I know. Barta was really great to interview and he was proud of the "SCRF." I did a few interviews with him that are worth the watch. I heard his wife died from cancer. If I ever see him again, I need to remember that and share my condolences.

I don't have anything more to add other than to say I miss my friend Bruce Smith. He wrote that piece.

That's him in this video doing the burnout:

Just watch the first 20 seconds and you'll see it.

Funniest damn part of that video. You couldn't see it but off to the right was this mobile home in the woods. We do the burnout. These redneck southern boys come out with mullets and cans of beer.

"HELL YEAH BROTHER!" "YEEHAW!"

Bruce and I were cracking up.

 

[testerdahl]

Very sad about your friend Bruce and sad that RAM discontinued the ECODIESEL.

yeah that came out weird. I'm not sure if Bruce is still around. Last time I heard from him was about 5 years ago. His wife had some medical issues and he retired mostly to take care of her.

 

[yammahaw]

My cost for the oil change I did myself was about $65 for ACDelco DexosD 0w-20 and a PF-66 filter. I'll be doing all my own aervice work. I'm planning on 5k intervals for oil and tire rotation and 10k for fuel filter and air filter.

Seems like the maintenance cost is is similar to that of a gasser. I would probably elect to just have the dealership do it as the cost increase may be minimal or so it is for a gas truck. Also what is the average for all the other filters outside of the oil filter?