GMC AT4X - Diesel or Gas?

[nabatron]

Hi everyone,

New to the forum I’m currently driving a 19’ ram rebel and going to be trading it in for a at4x. Was wondering with everyone’s experience with diesel and or gas which would you prefer and why?

I’m leaning towards diesel and with GM announcing the at4x having the diesel option in 24’ models it looks enticing.

It will be my first diesel so what are some pros and cons between diesel compared to gas!

 

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[Andystoy AT4]

My choice was diesel and still is the LZO with 10 spd powertrain. There are several threads on the pros and cons just as there are people with opinions. Do some reading and decide for yourself.

 

[mocomajek]

We got my wife a 22’ Denali Yukon Duramax which we’ve had for a year, and I just got myself a 22’ AT4 Duramax. I love em, super quiet but still sound like a diesel. Drive great around town and have plenty of get up when you need it. Not to mention the mpg is pretty good and I love how they tow. No regrets here after switching from an F150 Ecoboost.

 

[nabatron]

We got my wife a 22’ Denali Yukon Duramax which we’ve had for a year, and I just got myself a 22’ AT4 Duramax. I love em, super quiet but still sound like a diesel. Drive great around town and have plenty of get up when you need it. Not to mention the mpg is pretty good and I love how they tow. No regrets here after switching from an F150 Ecoboost.

How often do you guys have to put in DEF?

 

[mocomajek]

I haven’t really tracked it to be honest but it isn’t often enough for me to be annoyed by it or enough to really even remember lol.

 

[nabatron]

I haven’t really tracked it to be honest but it isn’t often enough for me to be annoyed by it or enough to really even remember lol.

Have you had any issues with the diesel?

 

[mocomajek]

Knock on wood, none. We both have about 11k miles on our vehicles.

 

[Teegunn]

I had a 2020 AT4 3.0 diesel. Loved the engine and truck. Great power, had snappy get up and go. Great torque for pulling my trailers. But early last December, the truck went into severe limp mode for the too common "service emissions system" warning code on the dash. I was working out of state at the time, and local dealership where I was at that I took it to had it 4 weeks, and replaced many sensors in different areas of the truck, but could never get it fixed. I had already been out of state for 4 weeks working, so being stranded out of state another 4 weeks was terrible.

On January 4th of this year, the dealer where my truck was at got in a semi with a bunch of new vehicles, one of which was a 2023 AT4X. I got the dealer to give me a really good trade price on my 2020 AT4, charged me nothing for the mounting "repair" bills since they had been working on it for a month (even though it was under warranty, GM was denying to cover the work being done, which was complete BS). I also got 5 grand off MSRP for the 23 AT4X. So I made the trade that day, and drove the 1000 mile trip back to MT where I live the following day.

The AT4X has the 6.2, and it is a thirsty engine. The power is great with the engine. As far as the MPG, my 2020 AT4 3.0 diesel got 5 to 7 MPG better than the 6.2 gasser. Given diesel is usually 50 cents to a dollar higher than gas, the hit to the pocketbook is about the same for fuel costs. I just have lower range on the 6.2 AT4X because like the 2020 AT4, it only has a 24 gallon tank.

DEF usage - my 3.0 diesel used DEF at a higher rate than others report. I would say I got about 2000 miles out of a 5 gallon tank of DEF on average. Living in MT with 8 months of cold and winter weather, plus pulling heavier trailers often as a contractor, probably has something to do with the DEF usage being higher than others who just drive theirs as a daily driver. But my wife also has a 2020 AT4 with the 3.0 diesel, and hers doesn't get much better DEF usage, so IDK.

Overall, I like the 23 AT4X better, because of the refreshed interior. I do like the get up and go of tthe 6.2 better, but the 3.0 diesel is no dog in any way. I personally wouldn't go with the 3.0 diesel again because of my experience with it at the end of owning it, however. I do think it is a great engine and powertrain, but the more complicated DEF/emissions system means that there is more chance for things to go wrong IMHO.

 

[Andystoy AT4]

22 Refreshed LM2 10 spd. no issues with engine and DEF use is minimal.

 

[mocomajek]

Forgot to add, my Duramax is a refresh as well.

 

[nabatron]

Knock on wood, none. We both have about 11k miles on our vehicles.

Nice that’s good to hear!

 

[nabatron]

I had a 2020 AT4 3.0 diesel. Loved the engine and truck. Great power, had snappy get up and go. Great torque for pulling my trailers. But early last December, the truck went into severe limp mode for the too common "service emissions system" warning code on the dash. I was working out of state at the time, and local dealership where I was at that I took it to had it 4 weeks, and replaced many sensors in different areas of the truck, but could never get it fixed. I had already been out of state for 4 weeks working, so being stranded out of state another 4 weeks was terrible.

On January 4th of this year, the dealer where my truck was at got in a semi with a bunch of new vehicles, one of which was a 2023 AT4X. I got the dealer to give me a really good trade price on my 2020 AT4, charged me nothing for the mounting "repair" bills since they had been working on it for a month (even though it was under warranty, GM was denying to cover the work being done, which was complete BS). I also got 5 grand off MSRP for the 23 AT4X. So I made the trade that day, and drove the 1000 mile trip back to MT where I live the following day.

The AT4X has the 6.2, and it is a thirsty engine. The power is great with the engine. As far as the MPG, my 2020 AT4 3.0 diesel got 5 to 7 MPG better than the 6.2 gasser. Given diesel is usually 50 cents to a dollar higher than gas, the hit to the pocketbook is about the same for fuel costs. I just have lower range on the 6.2 AT4X because like the 2020 AT4, it only has a 24 gallon tank.

DEF usage - my 3.0 diesel used DEF at a higher rate than others report. I would say I got about 2000 miles out of a 5 gallon tank of DEF on average. Living in MT with 8 months of cold and winter weather, plus pulling heavier trailers often as a contractor, probably has something to do with the DEF usage being higher than others who just drive theirs as a daily driver. But my wife also has a 2020 AT4 with the 3.0 diesel, and hers doesn't get much better DEF usage, so IDK.

Overall, I like the 23 AT4X better, because of the refreshed interior. I do like the get up and go of tthe 6.2 better, but the 3.0 diesel is no dog in any way. I personally wouldn't go with the 3.0 diesel again because of my experience with it at the end of owning it, however. I do think it is a great engine and powertrain, but the more complicated DEF/emissions system means that there is more chance for things to go wrong IMHO.

Dang that’s what I’m worried about the diesel is all the emissions garbage. Also worried if the dealer can’t fix the issue that I’ll he screwed since I live here in Canada and there’s no lemon law. Wife drives a 21’ yukon at4 with the 5.3 and we like it. Has decent power good enough to haul the kids around. My cousin has an elevation with the LM2 diesel and he loves it and has no issues. I want to go with the diesel just for the way better gas mileage.

 

[Andystoy AT4]

I live in Canada and have never needed the lemon law since my first new vehicle a 1969 GTO.

Only a small fraction of folks who drive vehicles are on forums and they are the ones that do require some help in getting their vehicle warrantied etc. but the vast majority of folks are not on forums and if they have problems they get them resolved. FWIW

 

[Teegunn]

Dang that’s what I’m worried about the diesel is all the emissions garbage. Also worried if the dealer can’t fix the issue that I’ll he screwed since I live here in Canada and there’s no lemon law. Wife drives a 21’ yukon at4 with the 5.3 and we like it. Has decent power good enough to haul the kids around. My cousin has an elevation with the LM2 diesel and he loves it and has no issues. I want to go with the diesel just for the way better gas mileage.

The complicated emissions system is more likely to have issues IMHO. Doesn't mean it will happen, but higher chance of it.

The better MPG is nice on the diesel. When I originally got my 2020 AT4 3.0, diesel was actually a bit cheaper than gas at that time. So a win/win on diesel being cheaper (not by much, but a bit) and much better MPG (5 to 7 mpg better on mine over a gas truck). But the cheaper diesel didn't last long. At this point it is close to a wash on fuel cost diesel vs gas. Just shorter range on the 6.2 given they both have the measley 24 gallon tank.

As an example on lifetime MPG, my 2020 AT4 averaged 16.9 mpg on the lifetime trip meter. So far at almost 10K miles, my 6.2 AT4 is at 13.6 mpg. My MPG is lower because I pull a heavier, high wind resistance 16' enclosed job trailer (that is loaded to the gills inside) with a tall ladder rack on top with 6 larger extension ladders on it. Lots of wind resistance pulling that trailer on mountainous hwys here in MT. So my lifetime MPG is significantly lower because I pull my job trailer (along with a couple other trailers) as a contractor. On normal driving with no trailer, I get 15 to 16 on the 6.2. 20 to 22 is what I got on the 3.0 diesel. Similar sized tires/wheels with front level on both, so same situation with both trucks.

 

[Cocoabean]

I bought my 2022 at4 with the LM2 in September. I have about 8k miles on it. Awesome truck, great engine and trans combo. I had some minor emissions issue early on (loose claps, NoX sensor unseated). The dealer took care of the issues and got me a 3-year service plan for my troubles. I love this truck and engine. I recommend it for anyone who wants V8 power with better mpg. DEF usage will align with your MPG. I have 35’s on my truck, so my mpg averages 20 and I use a take of DEF every 4k miles.