I went from a 2021 6.2 to a 2023 3.0 LZ0 and I'm loving it.

[JohnMr19]

I finally got to tow my cargo trailer this week.  7X14 Wells Cargo with household goods weighing approximately 5000 lbs total.  Got between 13 and 14 mpg with wind and lots of hills.  Overall very happy with how smooth the truck tows - the low-end torque is nice!  Used just under 2 boxes of DEF after 700 miles, so not as bad as I thought it would be.  First time I ever recived any DEF messages, but never got close to limp mode.  Actually used some oil as well - a first for that too.  Still love this setup though!

[anthonymason59223051]

On 8/8/2023 at 10:00 PM, seamus2154 said:

I have had several 6.2 and its a rocket ship. Loved that motor. Bought a 2021 denali with 3.0. Literally the best truck i have ever owned and the fuel mileage is fantastic. Tows like a boss. 2 days ago we went to the local dealer who had a perfect 1 owner, garage kept, maintained Yukon denali. Had the 6.2 motor and its for the wife so i was considering it. Very well versed with the lifter issue since 2020. It had 33k on it and was showroom new. Then read the Carfax a bit more carefully and saw the lifters had been replaced at 21K!!!!! I came to my senses and I will never consider signing up for that possiblity at the price point especially. 3.0 or nothing. 

i have a 2018 Silverado LT TexasEdition 4x4 with the 5.3 that i purchased preowned. it had 2 sets of lifters and a camshaft by the time it hit 78k. powertrain warranty and extended warranty kept me out of losing money. i am looking to upgrade to a 2024 or 2025 Sierra Elevation 4x4 with the LZO now that all warranties are lapsed at 104k. anything you might suggest?

[seamus2154]

12 hours ago, anthonymason59223051 said:

i have a 2018 Silverado LT TexasEdition 4x4 with the 5.3 that i purchased preowned. it had 2 sets of lifters and a camshaft by the time it hit 78k. powertrain warranty and extended warranty kept me out of losing money. i am looking to upgrade to a 2024 or 2025 Sierra Elevation 4x4 with the LZO now that all warranties are lapsed at 104k. anything you might suggest?

Don't hesitate. It is literally one of the best powertrains GM has out right now. I also have a 2018 Escalade for the wife with the 6.2 and 85k on her now. Literally listen to it everytime I start it just awaiting the lifter issue. My friends shop has done many. I am 3 years on my 3.0 and it is the best truck I have owned. All temptations to trade up stop me as my truck is that awesome. The 10 speed and the suspension are great. Also very quiet inside. Its a winner. I just did a full service, oil, trans, fuel filter, and differential, along with new Michelin defenders. Going from Florida to Montana. We have seven vehicles......and I chose this truck to go...if that tells you anything. I am in Fla and AC always on and get 22-28 mpg...6000 lb truck! 

On a side note was just talking with a neighbor who has an 2023 AT4 3.0 duramax. He has had 5 of them in his company. All of them have over 100K and they get new ones at 130K. Nothing but oil changes, and one check engine light...no warranty work on any of them. Good luck

[Gottsmoney]

All the 3.0 Duramax guys still loving them?  I have a 2022 Sierra Denali with the 6.2 and it failed on Monday.  No official diagnosis from the dealership yet but they found metal in the oil so new engine is on order.  I had planned to keep this truck for another 3-4 years but this engine replacement, although under warranty and I had planned on getting the extended warranty, has me thinking if I should look to trade it in for a Duramax.  

 

I've never owned a diesel but have familiarity with how DEF works.  I don't tow and have a mix of city and highway driving with a short daily commute to work.  The Duramax is appealing to me for the fuel mileage and what seems to be the reliability compared to the 6.2.  I've previously had many V8 GM vehicles (LS1 Camaros, 98 Silverado, LS6 CTS-V, 6.2 Escalade EXT, 2014 5.3 Sierra and my 6.2 truck).  For those that have had both the 6.2 and Duramax / how's the throttle response and regular acceleration?

[Port Tack Farm]

I love my Duramax.  My commute is 13 miles or about 25 minutes and the engine heats up well in that time, even in winter.  While I use the truck to commute some day's, we mostly use it to go to our property 50 miles away or for longer trips.  Short commutes are hard on all engines, but I think worse for diesel engines.  I'm not sure it does much damage, but I don't think you'll see the benefit of the better fuel mileage with short commutes.

[cautious optimist]

On 2/10/2025 at 7:10 AM, Port Tack Farm said:

I love my Duramax.  My commute is 13 miles or about 25 minutes and the engine heats up well in that time, even in winter.  While I use the truck to commute some day's, we mostly use it to go to our property 50 miles away or for longer trips.  Short commutes are hard on all engines, but I think worse for diesel engines.  I'm not sure it does much damage, but I don't think you'll see the benefit of the better fuel mileage with short commutes.

 

There is no getting around short trips in any vehicle. Grocery store, dropping off a kid to school, driving to church. Our days are full of short trips. I wouldn't worry too much about short trips; even a commute.
I just bought a new to me Sierra SLT 3.0. I have about a 10-minute, 5-mile commute. it ranges from 25-35mph. I'm getting 22-25mpg on that commute. I used to borrow my dad's F-150 Ecoboost when he was out-of-town. That same commute was roughly 15-17mpg's in his truck. I never saw his truck above 18.5, yet a 3 hour trip this weekend I saw 31.2 mpg's in the Sierra. In my short experience, you will see better fuel economy in all conditions with the 3.0. 

 

I compared the cost this morning after my third fill-up on my new to me SLT. The 3.0 is saving me about $12-$14 per fill-up for commuting and $20-$22 for long trips not towing. That's with Costco 87 octane gas at $2.85, and the local diesel station at $3.45.

 

I towed a 32' bumper pull trailer with my dad's truck a few weeks ago. I got 10mpg's on that trip. I'm towing that same trailer next week with my Sierra. I'll report back on the mileage after that trip.

[johnnyquick]

On 2/19/2025 at 1:06 PM, cautious optimist said:

 

There is no getting around short trips in any vehicle. Grocery store, dropping off a kid to school, driving to church. Our days are full of short trips. I wouldn't worry too much about short trips; even a commute.
I just bought a new to me Sierra SLT 3.0. I have about a 10-minute, 5-mile commute. it ranges from 25-35mph. I'm getting 22-25mpg on that commute. I used to borrow my dad's F-150 Ecoboost when he was out-of-town. That same commute was roughly 15-17mpg's in his truck. I never saw his truck above 18.5, yet a 3 hour trip this weekend I saw 31.2 mpg's in the Sierra. In my short experience, you will see better fuel economy in all conditions with the 3.0. 

 

I compared the cost this morning after my third fill-up on my new to me SLT. The 3.0 is saving me about $12-$14 per fill-up for commuting and $20-$22 for long trips not towing. That's with Costco 87 octane gas at $2.85, and the local diesel station at $3.45.

 

I towed a 32' bumper pull trailer with my dad's truck a few weeks ago. I got 10mpg's on that trip. I'm towing that same trailer next week with my Sierra. I'll report back on the mileage after that trip.

If it is a 32' enclosed, I will be VERY curious as to how it does, I mean I know you love your truck and all but GM is a huge failure in many areas these days.

[redwngr]

Update on my 1500 history:

 

I ordered 15 6.2 8 speed double cab. It was built early enough after change over that they weren't putting max tow and tow mirrors on 6.2's 8 speeds yet (at the time tow mirrors only came if max tow was added)

I'd been running trucks with tow mirrors for 10+ years and missed them. Decided I couldn't stop the extra price for premium fuel. 

Ordered a 16 crew cab std box 5.3L 8 spd max tow (so tow mirrors)

 

I track every fuel fill.

Doing my tasks, both trucks were always about 20 usmpg.

 

Doing the same job, my '21 crew std bed LM2, with tow mirrors, gave 26 (life of vehicle - 35,000 miles)

Decided I wanted the the new interior and also that I didn't like the T1 generation tow mirrors.

Ordered the current '23 crew std bed LZO. Regular mirrors instead of tow mirrors.

It's giving a little over 29 life over 29 life of vehicle. About 29,000 miles so far. 

 

 

 

 

Edited February 24, 2025 by redwngr

[redwngr]

It's now had bulk DEF added 4 time (and is currently showing about half)

Average def mpg - 1380 

 

 

I don't have the last fuel fill added to graph.

This 28,000 miles averaged 29.2 usmpg

[johnnyquick]

How fast do you drive it on the highway and what do you get then?

[JohnMr19]

I traded my '23 HC LZ0 about a year and a half ago for a '24 2500HD LTZ Duramax.  I had enjoyed the LZ0 so much, I wanted to try out the big diesel - plus I really liked the looks of the new 2500HDs.  The truck was a beast!  The low-end torque was amazing!  It had tons of pulling and passing power and rode very nicely on the highway.  It pulled my cargo trailer like a dream (didn't really feel it back there) and I could pass easily while pulling the trailer when necessary. 

 I had hoped the highway mileage would be close to what I was getting with the LZ0, but I was dreaming.  The best I had seen was around 18 - 19 with no headwind.  And while that wasn't bad and gave me a range of well over 550 miles, it was with a 36 gallon tank.  Other down-sides were the truck rode fairly rough/stiff around town, got about 12 mpg doing it, and my wife had a lot of trouble getting in and out of it.  Parking it in a crowded parking lot was also a factor.  I still loved the truck, but since I only tow a couple of times a year, I felt the truck was not really what I needed and had made a mistake.

 I decided to go back to a half ton with the LZ0 and I feel that was the right choice.  I ordered a short bed (parking ease) High Country with towing mirrors (one of the features I really liked about the 2500HD).  I didn't get the Max Towing package because my cargo trailer weighs between 5,000 to 7,000 lbs loaded and I only tow it twice a year.  I also wanted the Adaptive Ride Control for added comfort, which you can't get with the Max Tow Package.

 I received the truck last month ('26 model) and am very happy with it.  The truck rides like a dream in town and on the highway, has plenty of power for what I use it for, and I get great mileage doing it.  I travel quite a bit for my job as well, so the increased mileage was a big bonus.  My first trip out I made it over 540 miles at 27 mpg with 115 miles left on the 24 gallon tank.  I plan on retiring in a couple of years, so this truck will stay with me for a long time - I really couldn't see the 2500HD being my daily driver once I wasn't working any more.  I highly recommend the LZ0 to anyone considering it.

 

 

 

 

 

 

Edited October 20, 2025 by JohnMr19

[Z45]

I see comments about DEF use and miles.  GM service info

 

The amount of DEF consumed also is a function of how hard the engine is working, or engine load. Due to engine use, it is more representative to compare DEF consumption to the amount of fuel consumed – also a function of engine load – instead of miles traveled. In addition to engine load, other factors that affect the DEF usage rate are the humidity, temperature, and altitude where the vehicle is operating.