What’s the consensus on the Duramax reliability?

[BlackHC2025]

2025 Tahoe HC with 8,800 miles and LZ0. Had a 2013 with 5.3 and 6 speed, over 75.000, mostly urban commuting. No comparison between the two. LZ0 all the things; mileage, performance, ease of maintenance and range. Thrust bearing, what me worry? Nothing yet.

 

[Flathead40]

We just hit 20k miles on our 25 Yukon XL AT4 and have averaged 23mpg. We do a lot of highway and interstate (80mph +) driving and live where high wind is an everyday fact of life. No issues with the LZ0 so far. We’ve been using Hot Shots EDT Winter Defense in the cold weather, but probably don’t need anything. DEF usage is hit and miss, but it’s about 1k miles per gallon. Came from an Expedition that averaged 18 in the same driving and a friends 5.3 Tahoe averaged 17 in similar driving. Also the oil pump belt service interval is 200k on the LZ0, instead of 150k on the LM2. The power delivery is well matched to this kind of vehicle with nearly 500f/lbs. of torque. If you want to win at the stoplight, get a 3.5 H/O Expedition.

 

[JayceeP]

We just hit 20k miles on our 25 Yukon XL AT4 and have averaged 23mpg. We do a lot of highway and interstate (80mph +) driving and live where high wind is an everyday fact of life. No issues with the LZ0 so far. We’ve been using Hot Shots EDT Winter Defense in the cold weather, but probably don’t need anything. DEF usage is hit and miss, but it’s about 1k miles per gallon. Came from an Expedition that averaged 18 in the same driving and a friends 5.3 Tahoe averaged 17 in similar driving. Also the oil pump belt service interval is 200k on the LZ0, instead of 150k on the LM2. The power delivery is well matched to this kind of vehicle with nearly 500f/lbs. of torque. If you want to win at the stoplight, get a 3.5 H/O Expedition.

My ‘24 Yukon XL LM2 says 200k for the oil pump belt as well.

 

[Flathead40]

My ‘24 Yukon XL LM2 says 200k for the oil pump belt as well.

They must have updated interval in the later years of the LM2. Used to be 150k. Keep in mind the part didn’t change, just enough data for them to reliably extend the interval.

 

[CAPantherFan]

13,000 miles on LM0 and loving it! It's quick off the line, fuel efficient and fun to drive!

 

[BacDoc]

This is a 2 year review of the 2024?Duromax.
Yes they are trucks but it’s about the engine and transmission so I thought it would be relevant.

 

[BlackHC2025]

'25 Tahoe HC, 9,800 miles now, still 24 OA mpg, love my LZ0, May build.

 

[Scarey]

‘25 tahoe hc duramax, 8,700 miles, all good.

 

[JayceeP]

This is a 2 year review of the 2024?Duromax.
Yes they are trucks but it’s about the engine and transmission so I thought it would be relevant.

Really good overview. Not filler fluff crap just all useful content.

 

[Stbentoak]

21 doing well 48k miles... 25 doing well 6K miles... Only issue? Diesel is 5.69 here....

 

[Fless]

21 doing well 48k miles... 25 doing well 6K miles... Only issue? Diesel is 5.69 here....

All I can say is

 

[JayceeP]

21 doing well 48k miles... 25 doing well 6K miles... Only issue? Diesel is 5.69 here....

We are $6.60/gallon USD in my part of Canada. Diesel is always a bit higher on the east coast. It’s sub $6 in places like southern Ontario/Toronto

Premium is about $5.10 so I’m probably still farther ahead than the 6.2 but at this spread the difference isn’t much. However I still enjoy the range and the low fuel consumption.

Oh - on that note, no issues with my ‘24 Yukon XL SLT LM2. Only 22,000km on it though. Trying to upgrade to a ‘26 XL Denali diesel but that’s proving to be a challenge lol.

 

[sdp9427]

25 Yukon Duramax, absolutely love it. Nearly 600 mile range on a tank, only uses 1 bottle of DEF per oil change.(My 6.6 loves that stuff). My dealer gives lifetime powertrain warranty with sale, have to maintain perfect records for that though. I'm good to go getting 25 to 29 mpg consistantly.

Lifetime powertrain warranty on a Duramax? I don’t think I’ve heard of such a thing. May I ask what dealer and what exclusions?

 

[Stbentoak]

Lifetime powertrain warranty on a Duramax? I don’t think I’ve heard of such a thing. May I ask what dealer and what exclusions?

There are dealers in Florida that offer the same thing. But the big twist is you have to bring it to only them for maintenance and you have to do it at a more aggressive schedule than recommended by the OEM. If you miss one lick on their requirements..... the warranty is void. Meanwhile they are soaking you every time it comes in for something you could do yourself at 1/3 of the price at a schedule you choose. It's just another dealer scam to make you think that they care about you. Never buy into this BS. I'll do my own service and take my own chances.....

 

[randeez]

coming up on 90k miles on my 2020 (owned since 26k) silverado
no leaks, no ccv, no def/dpf problems,
biggest fix ive had to do was the injector harness - would get code like once a month for it, diy sucked but harness was cheap

 

[Padraig]

Approximately 48,000 on my 2021 Suburban. Have done nothing but routine mantaince. Runs like a swiss clock. It also does a great job of towing my 6,000 # boat.

Padraig

 

[Jus Cruisin]

Older thread but I'll be ordering the 3.0l in the Yukon. I tow my enclosed car trailer with my Sierra easily. I expect the same with the Yukon. Diesel is less than premium (6.2l) around metro Detroit.

 

[dbphillips]

i would not. i have a '25 SLT 1500... pulled a 5000 lb last trailer year... and now the engine is pretty noisy.... also.. if you tow anything... it gets no more mileage than a 5.3 and uses lots of DEF. also the "regen" function is about 10 minutes every hour. not any good mileage during that period either.

i have had lots of oil burners... gas and diesel used to be about even in price... now gas is a lot cheaper. DEF is $18 bucks for 3 gallons.

i am going to under my 3.0 and look at the inspection plate under the bellhousing see if the crank has motion.. they are losing thrust bearings.. in '25 and '26.

There is definitely something wrong with your engine.

 

[Padraig]

There is definitely something wrong with your engine.

Yep, I agree. Last weekend I towed my 29 foot boat from far western New York to Seneca Lake and back. Total round trip miles is approximately 350 miles. Average mpg was 17.8. Def hardly moved. Maybe only line on the gauge. Most of the trip was on route 86 which is quite hilly. When you get on the finger lakes region it is extremely hilly. Amazing how well the baby diesel handles the hills.

Padraig

 

[BlackHC2025]

10,800 5w-30 c3 oil and a PPE filter, a couple hundred miles ago. Hasn't blown yet.