'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.

 

[NMTRUCKER]

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.

OK, buckle up and pop a top as Tim says! I own a ‘23 GMC SIERRA 1500 with the LZ0 3 liter diesel. GM designed this motor to be a fuel efficient daily driver. It is not designed to haul massive loads although it can tow I believe 10,000 pounds.
I did a 1 year review of my truck on this forum. Check the sub forum category GMC SIERRA if you’re interested. Why did I buy a truck with the LZ0? I live at 7,500’ and at that elevation a normally aspirated gas motor loses 20% of its rated horsepower and I was getting 13-15 mpg in my Silverado.
1:REGENS: REGENS take about 12 minutes driving at highway speeds. The more stop and go driving you do the more REGENS are necessary. I bought a BANKS IDASH gauge that plugs into the OBDII port. This gauge can be setup to monitor the DPF soot level and let you know when the vehicle goes into REGEN as well as a plethora of other parameters (highly recommended). The digital instrument cluster will also warn you when the DPF gets overfilled to drive at highway speeds to complete a REGEN. I average 300-400 miles between REGENS.
2: DIESEL EXHAUST FLUID-As far as I’m concerned DEF useage is a nonissue. Generally in a non towing situation DEF is used at a rate of 1 gallon per 1,000 miles. So you would use about 8 gallons of DEF per year at a cost of less than $25.
3: MAINTENANCE-My truck has just over 14,000 miles and the only thing I have done is change the oil and filter and had the tires rotated and balanced. I did change the fuel filter at 8,000 miles only because I was curious what it looked like. The cost of an oil change if you DIY is $50 for oil (AutoZone sells Mobil 1 ESP X2 0W-20 in a 5 quart jug for like $37) and a PF-66 oil filter is under $7. You will have to use a diesel antigel additive during the winter. I use a brand called Power Service locally available at AutoZone.
WEAR & TEAR - I park my truck in my shop which doesn’t get below 32 degrees and so I have never plugged in my block heater. I’ve never had any starting issues.
DAILY DRIVING COSTS - My truck has averaged 28 mpg over 14,000 miles of driving (hand calculated). I guess the other cost would be DEF (a half penny per mile).
In summary, my shortest drive is 35 miles one way and I never use my diesel to run to the mail box which is 3 miles away. I also drive over 125 miles one way a couple times per month. I am an admitted fanboy of the GM 3 liter turbocharged diesel. However, in your driving situation I would steer towards a gas motor because you seem to drive short distances in cold weather which in reality is not good for any motor but especially a diesel. Hope this helps and good luck with your truck purchase. Please keep us updated.

 

[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 ?

 

[NMTRUCKER]

@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 ?

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.

 

[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.

 

[NMTRUCKER]

I s

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.

I started off looking at the RAM ECODIESEL (3rd generation). But the more I read the various RAM forums made me shy away from that diesel engine ( and just a couple years ago it was discontinued). Next up was the new Tundra with the twin turbo that I ordered in ‘22. After 61/2 months it never showed up. Before that I started looking into the GM 3 liter diesel and at that time it was the LM2 first generation. Except for some no start issues(eventually traced to a bad batch of starter wheels) there didn’t seem to be a lot of issues. Then Tim did an extended interview with the lead engineer (John Berta) of the LZ0. That video really cemented my decision to go with a truck with the LZ0. Like you, I have never owned a diesel truck (just a 3 cylinder diesel tractor) and like you I have 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.

 

[NMTRUCKER]

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?

Yes you’re right about the DPF location. Also there are two EGRs a low and high pressure variant that minimizes the soot reintroduced into the motor.
During my 18 months of ownership I had one CEL but that was only for a software update. Normally these updates would be handled during maintenance visits to the dealer. But I do all of my own maintenance but I did take it to the dealer for the update (free of charge).
My work background was in engineering and physics. I spent 34 years collecting and analyzing data to prove or disprove the PhD’s theories. So I guess you could call me a nerdball. I also worked with GM.engineers and physicists for five years to develop a process to replace steel cylinder liners.
So the first thing I did when I bought my truck was to purchase the BANKS IDASH to understand how the emission system was functioning. I wanted to know when I was approaching a REGEN so that I could drive accordingly. But that’s just the way I’m wired.
Many people just get in their diesel trucks and drive them and aren’t concerned about how the emission system is functioning. I think the GM LZ0 design engineer would say just drive it and don’t worry about it. So for your driving situation you might very well have a good experience with a 3 liter diesel but if it were OCD me I would stick with a gas motor.

 

[NMTRUCKER]

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.

There are DPF cleaning services in the US. Apparently it’s a 2-step process. After removal the DPF is weighed then subjected to a pneumatic-pressure/vacuum cycle to blow out particulates. Then the second process is an 8-hour baking to remove sulphate and oil contaminants. Then a final pneumatic-vacuum rinse. This service is supposed to return the DPF to a new condition. The one vendor I saw was about $1,000 to $1,200. I don’t know how much a brand new GM DPF cost for comparison purposes. I guess a lot of semis use this service. Interesting.

 

[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.