Top GM 3 0L Duramax Diesel Questions Answered - DEF, Regen, Oil, Additives

Shopping for a new Chevy Silverado, GMC Sierra, Chevy Tahoe or GMC Yukon and curious about the GM 3.0L Duramax diesel? Our Publisher Tim Esterdahl owned one, interviewed the chief engineer and published dozens of videos. In this video, he addresses the top questions he still sees online about this small turbo-diesel engine.
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[@jayray274]

Best engine GM has developed in decades.

[@Pickuptrucktalk]

1000% agree.

[@nowayoutstp4]

Almost got 800miles to a tank a few times. Works great at high altitudes too, had mine over 10k feet elevation a few times. 2024 TB slate gray

[@davidporter7051]

I agree and I've owned everything from the 4.3-6.2.

[@Veterans-e2c]

Agreed love my 2024 gmc sierra 1500 Denali best truck on the market and good dealers are doing crazy discounts and incentives and interest rates. Saved 15k plus Costco 1k incentive and vet incentive $500 paid with extended warranty and maintenance plan 80k all in.

[@dfjanes]

Great video Tim. Just a note about fuel economy and DEF usage. I had a ‘23 Sierra 1500 AT4 3.0 Duramax (LZ0). When towing, even a small increase in speed dramatically changes your diesel/DEF consumption. I’m up in Canada and I found the towing sweet spot with that truck / engine was between 100-105 km/h (~63mph). Towing between 3,500 - 5000 lbs at that speed, the mileage/DEF consumption was great. When I set the cruise at 110+km/h (~70+mph) the fuel/DEF consumption was alarming. As you state it absolutely drinks DEF, I actually ran my DEF tank empty once on a trip because I didn’t realize how fast it was hammering through it. That’s just how it is when towing…if you can back off the speed a bit, it makes a huge difference. Otherwise, crack open the wallet and get ready to pay. I had to move on from the ‘23 Sierra, living in Northern Canada(Northwest Territories) with extended periods of extreme cold I had some problems my dealer/GM could not solve with the LZ0. Other than that, that truck engine combo was just excellent. I have ‘24 2500 Sierra AT4X with the 6.6 now and it’s the same story with fuel/DEF usage. Keeping that truck below 70mph makes a huge difference when towing. I just did a 4,500 mile road trip, towing the whole way (4000lb enclosed), and when I cruised under 110km/h (70mph), the truck got great mileage and was easy on DEF. At some points when I just wanted to make some time up, it hammered through DEF and diesel. I knew it and I was ok with it. Enjoy the channel and your videos Tim, keep up the good work. Dave

[@PlayWaves1]

I'm not a GM guy but this engine is a masterpiece. Great fuel economy, great power, low upfront cost.

[@Kookaburra4509]

Thank you for putting this together! I just bought a 24 AT4 with 3.0 diesel. I love the truck. I watched a bunch of your videos as well as DemonWorks before I made my move. I couldn’t be happier. Thanks for your input and insight. 🙏🏻

[@angelolamantia]

Great explanation and dispelling the myths of modern diesels

[@davidporter7051]

I have a 23 and couldn't be happier.

[@corvetteman7232]

I had a 2020 Silverado 1500 and currently have a 2022 Suburban with the 3.0 LM2 motor. Neither burned a drop of oil in 5,000 mile oil change. Also, the DEF usage was reasonable. This is an awesome motor.

[@shawnl4139]

I am so relieved they’re keeping it. I have a 2021 with 75k miles and no issues with the engine. Came from a Ram 1500 with the Ecodiesel (no issues either). Tows my boat great, I use the payload for work, and great MPGs all around. Best 1500 engine combo.

[@Gameplayer70]

I eventually got my own 3.0L this year, and I absolutely love it! Everything you said is spot on, and people really need to just not be afraid of it. It's an absolutely amazing engine, and I look forward to many, many years of great mileage out of it.

[@randybailey2794]

2024 LZ0 models had check engine light issue related to regen until TSB came out in May for an update to the ECM. No problems after the update so far.

[@chaseydog7956]

Same here. I had a CEL at 3000 and then again at 8000. Got tge TSB done, and I'm at 10500 without any more CEL's

[@angelolamantia]

The people that complain about the oil pump belt don’t own the engine and are not going to buy one anyway.

[@chaseydog7956]

Great video, Tim. I have just over 10,000 miles on my 24 AT4 3.0L and absolutely love it. Best engine I've ever owned. Agree with you on regen. I stressed about it early on, but don't give it a second thought now. Nearest Top Tier to me is about 1000 miles away. Recently started using Archoil AR6400-D diesel cleaner every 5000 miles. Small increase in mpg but a pretty healthy increase in miles between regens.

[@BrianNC81]

Very happy with our 2022 suburban LM2. No issues but only 24k miles. I think it regens about every 400 miles. I can tell when it is doing a regen by the exhaust sound and high idle when stopped. I buy the Walmart DEF for 8.88 and no issues. Use mobile 1 esp x2 DexosD oil from Walmart for oil changes. Hot shots EDT fuel additive to keep everything clean. Also have a 3.0 inline 6 twin turbo diesel in my old bmw with 162k miles on it. Its a blast to drive with 364whp/595lb torque in a small 3 series (stage 2+ tune). Pulls a mid 12 second quarter mile at 111mph trap speed. Fun fact, the fastest 335d 3.0 diesel in the US is pushing over 1000whp with triple turbos and nitrous.

[@bertwilson4311]

One of your better videos. The only omission/correction I would add relates to cold weather. As someone who lives 130 miles outside of Fairbanks, Alaska, I find that all diesels these days start just fine without being plugged in even down to -40, at which point plugging in helps. Block heaters do greatly reduce cold-start wear, however. What will shut down a diesel in the winter is improper winterization of the fuel. If you fill up during the shoulder season and the station has not switched to the appropriate blend of No. 1 Diesel/No. 2 Diesel, it can catch you during a cold snap. Likewise, if you use the huge range many of these vehicles have and think you will fill up in balmy Washington state and save by not refilling until you get to Grand Prairie, you may find yourself at the side of the road. We have lows of 2 deg F coming up tomorrow, and I made sure to keep my vehicle's fuel tanks low so I can fill with the appropriate winter blend.

[@7171-Ws6]

Best engine I’ve ever had…..

[@TheKoreanStarrbuck]

I bought my first baby diesel earlier this month after watching most of your videos about this engine. I don’t regret my purchase and absolutely love this truck.

[@timmurr1672]

I just made a three hundred mile trip in my new Yukon SLT with the 3.0 and got 28.2 MPG.

[@chrisd4251]

Thank you for this video. Hope others watch it if they are on the fence with the diesel because you nailed it on the head. Bought a used 2021 with the LM2 not knowing anything about diesel trucks, but did plenty of research. I’ve put about 25k on it, and as long as they keep making them, I’m buying. Love everything about it, and everything you said in the video about regen, cold starts, def, etc, I agree 100%. I average about 21 mpg because of mainly city driving, but have hit 34. My 5.3? Best was about 26, average of 14. Never looking back.

[@koharu.mochii]

I came from your other video but thank you for this video too. I'm new to learning about cars but I've watched many car enthusiasts like Joe Raiti, Sofyan, and Doug's videos regarding the duramax engines in the Tahoes being really good but never understood the DEF system, regen, etc. Thanks for going into more detail, this makes me feel comfortable about buying the duramax engine option. The mpg's are much better on this option which I love, but I do know it's much more maintenance than the 5.3L or 6.2L options. Diesel is not that bad either, I'm in California and at the shell gas station it's $3.05 right now which is better than the $4.29 I filled up at today lol.

[@donniem6191]

This is the only engine I have been excited about in the recent years. I honestly wouldn’t be shopping for a truck if it wasn’t for this engine.

[@alaskanlife4980]

Well im 3 weeks in w this eng in a 24 rst silversdo beyond impressed !!!!

[@BearPapa49]

I was going to buy the 2024 Chev 1500 inline 6 diesel . Great truck ! Excellent mileage for a truck . I went with the 2024 Chev 2500 diesel duramax ! I’m gonna tow a travel trailer soon and since I’m retired gonna see some sights in different states ! Go Diesel ! Great trucks ! DEF 13.99 from Costco ! Not a problem no issue. I only buy it when I need it . I don’t store it !!! No big deal

[@AlaskaErik]

I have this engine in my 2024 Sierra SLT. It is an absolutely amazing engine. I drove from Alaska to southern Arizona a few weeks ago and fuel mileage was amazing. I topped off before leaving Alaska and I needed only three fill ups to get through Canada. Another three fill ups in the Lower 48 got me all the way to my destination southern Arizona and I still had half a tank left. I can't say enough good things about this truck and its engine. I loved the 6.2L in my 2019 Silverado, but it just doesn't compare to my 3.0L.

[@kck66808]

My 2022 Tahoe RST duramax has been awesome. 42,000 trouble free miles. Lots of city driving. Around 7,500 miles out of a tank of DEF.

[@dalelong4716]

I've got a 23 Silverado with the LZ0 3.23 gears towing is 9300. Heavy duty towing package brings towing just over 13000 lbs with the corresponding hit to your mileage.

[@down_yonder]

why did you buy a pickup truck with highway gearing?

[@cstgx]

13k is way too much weight for that engine. I was towing 7500 and losing speed up hills.

[@tnebbie3230]

@@down_yonderthe majority of theses trucks have that gearing which works just fine with the 10 speed transmission

[@tnebbie3230]

@@cstgx13000 is only if you have the max tow package which has lower gears

[@ar15gator]

Good video, realistic viewpoints of today’s diesel pickup truck and its ownership. In conclusion, today’s diesels are not something that will last hundreds of thousands of miles maintenance free with repairs, in comparison to the first generation diesel trucks, 200,000 miles to have to change an oil pump belt with an exorbitant cost associated with it, just insane, IMO, something that was unheard of years ago. They are not making diesel trucks to last any longer without having a huge repair bill, literally cab off engine repairs, which is just plain horrible considering that a diesel truck today is anywhere from over $60,000 to $100,000 plus, depending what you’re getting. Another disposable vehicle costing us our hard earned money too early.

[@mhark2043]

I have a 2020 Sierra with the 3.0 and love it. Great fuel economy and with it mated with the 10 speed the power is very linear feeling. Pulling my 5500 camper it is always in the right gear.

[@clarkwgriswold157]

Must admit, after 30 years of diesel ownership in the UK, I’d never heard of owners idling their diesels. Short trips on the other hand yes. Engine doesn’t get a chance to warm up correctly and DPF filter blocks. General advice is to drive on the Freeway/ Motorway for a few miles holding a lower gear to burn it off. If not, it’s a trip to the dealer for a DPF clean. Only ever happened to me once though admittedly, DPF filters are relatively newer. Now, if the CX-5 has been used for a few weeks over shorter journeys then I will do the Freeway/ motorway run. Not required in our other car which is a BEV. 👍

[@darrena8439]

I have a 2020 Sierra with 52K. First diesel I have ever owned and wouldn't consider any other engine on my next vehicle. This thing has great fuel mileage and plenty power for towing.

[@MattN03]

I'm considering switching from a 08 F250 V10 that tows 5k-7k lbs about 5k miles/year and sits in the garage otherwise to a 3.0. I think a 1/2 ton would be ok with that weight and would let me have a single vehicle as a daily driver, road trip vehicle, and tow vehicle and get rid of having a car and truck.

[@ar15gator]

Great plan!

[@texas737pilot]

I love this in my Sierra and was hoping to get my wife a 3.0 in a 2025 Yukon Denali Ultimate…but GMC isn’t offering it in the top trim next year. A huge mistake IMO.

[@TomSzalkucki]

I don't have this particular engine but I do have a small diesel motorhome that requires DEF. I buy most off my DEF at truck pumps. Put the nozzle in the DEF tank fill opening and pull the handle just like a fuel pump. It will auto shut off just like a fuel pump. A lot simpler than the plastic jug and less packaging waste.

[@rickschwartz2447]

i hope gm makes a larger number of 3.0 trucks hard to find them

[@davidporter7051]

in 2025 GM is increasing the 3.0 allotment. It's the 2nd fastest selling engine option.

[@thesandman775]

I sincerely hope they don't do something foolish and abandon this engine. They have something great on their hands

[@stevenanderson1430]

This engine has given me nothing but problems. It has never stranded me, but all of my issues happened in the after treatment system. Tons of sensor issues. They replaced multiple and even the ECM. It also had issues towing and major defects consumption. I loved the power and fuel economy of this engine, but ultimately had to turn my 2024 ZR2 in under lemon law. Luckily GM made the process smooth

[@BobPritchard]

Wish they had this engine in the current Colorado. That's why I'm still driving my last gen Diesel Colorado.

[@viziocamaro]

I have a 2020 crew cab Silverado with the diesel. I get 29 mpg that’s driving in the city and some hwy at 55mph.

[@BabyGators]

I’ve never had a better feeling engine and truck than my LZ0

[@rodgood]

Just imagine the fuel economy and reliability, if on the ground diesel owners had the same emissions requirements that the aircraft industry gets .

[@BZ1340]

After watching this. whats the cold weather adaptability i’m talking -20 up to days of -35 … where I work its no plug ins… So we have to leave our vehicles 7 or 8 hours…it was getting my attention t’il I thought of this as of a concern..

[@brandonb2761]

Auto start stop eliminator shouldn’t be used based on the idling recommendation?

[@tnebbie3230]

It’s fine. Just not great to let it idle for hours on end. Not great for the emissions system.

[@josephbreen9955]

That is the best motor that gm has made

[@jnmaher1967]

Tim should ask the engineers if they had to pick another competitor’s engine what would they choose.

[@Pickuptrucktalk]

Man that’s a great question.

[@KPHVAC]

I'm seriously interested in the GM 3.0 Duramax. I've seen video's of people getting close to 30 MPG highway in a full size truck!!

[@neddles-jz5cr]

4dr.and 6’7” bed here and I average 32-34 on 2 lane highways, 27-31 on interstates.

[@scottymoondogjakubin4766]

Not many ever seen a cut away if of a DPF ! Its definitely an exhaust restriction ! So the EPA thinks dumping fuel into the exhaust stream to keep it clean only burns more fuel ! Trucks with the 3.0 would easily pull off 30 + mpg without all the BS ! And not to forget ?DEF ! At least it helps keep the DPF clean ! But at a cost ! About a gal every 1,000 to 1,500 k miles

[@CharlesAnsman]

GM should warranty the belt for 200K or 15 years plus any damage if failure before said limits

[@davidporter7051]

nope.

[@TonkaFire2019]

Just found out if the truck loses power you can’t put it into neutral. My 24 lz0 left us dead in the road. Apparently it’s a safety program in the new current vehicles. I have 12k on it and it uses a full tank of def every 5,400 miles. And yes you have problems with short tripping i continue to get CEL if drive short distances.

[@tnebbie3230]

May need to take it in for the Tsb software update

[@wilmarbarrick3194]

We need to get you back in that sub-zero artic cold. Makes the rest of us feel toasty at 30.

[@Pickuptrucktalk]

Screw that!

[@cdeamel6066]

Hello what about oil consumption?

[@genehart261]

If you are looking for a new truck and you drive one of these trucks you will buy it!!!

[@davidgrisco1939]

Can I get the diesel in a 2025 RST trim Tahoe? I don't see an order webpage yet.

[@Pickuptrucktalk]

Yes it should be available when the build and price goes live.

[@wayneanderson991]

Hi Tim, you might want to show annual cost of operation for say 15,000 mile per year for this diesel vs gas. Include oil changes, fuel filters and DEF along with the average cost of the fuels. Even though the mpg might be better in the diesel I don't think you will see enough of a fuel economy cost savings to justify the diesel as being more cost effective over a gas engine. I have owned 9 diesel pickup trucks since 1998, two of them were Ecodiesels, and unless I towed all the time with the diesel it was never cheaper to run over gas on an annual basis. I love diesels but never found them cheaper to run unladen as a grocery getter, gas was always better for a daily driver.

[@ar15gator]

Agreed! 💯

[@Pickuptrucktalk]

Not saying they are or aren’t more cost effective. Besides, how do you factor in towing? I didn’t do a lot of towing with mine. Also how do you factor in skipping gas stations? I find that saves me lots of money since I don’t have to stop so often. Pencil and paper is a nice idea, but doesn’t always compute with various undefined factors.

[@wayneanderson991]

@@Pickuptrucktalk I don't know but I seem to pass quite a few gas stations with my 2024 F150 Powerboost. Don't have to fill with DEF and don't have to work my time around regens with short trips. Like I said I love diesels, have own quite a few in my time. The only real issues I have had with any of the current generations of diesels have been with the after treatment systems. Short trips on a regular basis is just asking for trouble. You need to own one of these new diesel trucks for more than year to be able to tell people not to worry about owning a modern diesel. One year of ownership of a new truck doesn't mean a thing in terms of reliability and cost of ownership. I have run diesel pickup trucks for 26 years now so this is not my first rodeo.

[@dpg2826]

I do 8-12 hrs road trips 2-3 times a month up in Canada. Highway trips average 31-33mpg. Usually lots of hills and mountain passes. The comfort of those drives over my last 2 5.3's is night and day. Eliminates the countless downshifts climbing, especially nice in the snow and ice. And the descents with the exhaust brake and not pumping brakes is awesome. Just paddle shift to the rpm sweet spot and enjoy the drive. I am at 101k kms, and brakes are still at 8/9mm. Says 86% on the display. My last 6.6 Duramax first set of brakes were at 260k kms. Brake pedal is for stop signs. It is cheaper overall and almost therapy on long drives over gaspots.

[@ar15gator]

@@dpg2826 Great Share! Thx 💯

[@williampropp1290]

I really like mine!

[@aroundthegroundlandscaping7107]

I not afraid of it they just don’t offer it in a regular cab short bed truck or I would have bought it not 2.7 turbo is a bad engine and really like it so far just would love to have the diesel

[@Kdavis8377]

Take the intake off one after 35k miles and look at the carbon buildup. Then you’ll get nervous, lol

[@down_yonder]

yes sir Ill never own another usa diesel again. USA diesels are not diesel trucks any more. they are choked out over complicated hot mess. Simple gas motor is what you want.

[@Pickuptrucktalk]

Carbon buildup? That’s still a thing for you.

[@Kdavis8377]

@@down_yonder yep. I’d pay 50k for an old 95 7.3 Powerstroke with 25k miles. Todays diesels get great mpg’s, and a very smooth engines but they’re maintenance nightmares and the carbon buildup is absolutely awful. In no way is that good for an engine and it’s why you see them being rebuilt at 100-125k now on a daily basis. Such a shame.

[@Kdavis8377]

@@Pickuptrucktalk talk to some diesel mechanics. Most think it’s needs to be a maintenance item every 35k miles. But I’m sure you talked to a GM engineer and he told you carbon buildup inside the intake isn’t a big deal.

[@Pickuptrucktalk]

@@Kdavis8377 I talked with mechanics. I talk with them all the time.

[@kaivonmortazavi8656]

Well put!!!

[@KPHVAC]

A serious downside with the 3L diesel is the belt at at the back of the engine that runs the oil pump. This needs to be replaced at 150,000 miles and requires the transmission to be removed. That's a $3,000 repair.

[@vm2003]

3L diesel with LZ0 its 200k interval for changing the belt vs 150k mile interval on the 3L diesel LM2 version.

[@tnebbie3230]

He spoke about this. They are 200,000 mile interval now.

[@kelviskelvis7140]

I look at this engine choice as a good short gap placeholder for fuel economy purposes in the GM fleet until electrification happens for this Tahoe SUV. (It has already started with the 2025 Escalade IQ) The Silverado has already had the EV introduction into the line up. GM's engineering has done a very good job to make their product line competitive as electrification transfers through the vehicle fleet. The Silverado EV is a home run for GM. It just sucks that we are in this transition time between this older ICE tech that will phase out and the newer propulsion that will give an overall better driver experience and operate cheaper than this placeholder tech. BTW the 2025 Silverado EV in LT trim OTD pricing is already on PAR with 2025 ICE versions and the EV LT is cheaper to operate by 2/3 the cost on average. Something to consider if you are thinking of purchasing in today's market. The 2025 market has tradeoffs to keep in mind.

[@davidporter7051]

simply no. One there isn't enough rare earth metals to make EV a viable market not to mention the power grid isn't sufficient to make EV for everyone an option.

[@kelviskelvis7140]

@@davidporter7051 That is not correct. Try agian to be more accuate.

[@davidporter7051]

@@kelviskelvis7140 you can't refute fact with try agian. Your original post is a cause for concern because it's propaganda not fact and then you don't understand the process to make the propaganda into a fruition isn't viable. What is agian?

[@peiguy1982]

You owned yours for the first oil change.

[@JonZimmerman-t3e]

Tim I would think that if you only got replace the belt every 200000 miles I bet you can get half million miles on that motor if tooking care of

[@josephbreen9955]

In my 21 gmc 3.0 i got 43.8 miles to gallon. Freeway and city i would get 32

[@kc0jhs1]

9300lbs tow on the lm2

[@angelherrera2151]

The transmission is what has problem. I know more than 5 cases with the same issue in the transmission Forget the oil and DEF consumption. That is not a problem. I had a 2013 Impala and transmission issues as well.

[@Pickuptrucktalk]

Your Impala has the new 10 speed?

[@tnebbie3230]

@@Pickuptrucktalk😂😂

[@jordanreyes8880]

Love my Sierra with the LZO

[@nowayoutstp4]

Same in the Trail Boss variant.

[@tnebbie3230]

13000 lbs is only for the max tow package

[@Pickuptrucktalk]

And?

[@tnebbie3230]

@Pickuptrucktalk I was just clarifying that it is only that amount for the max tow packages with the lower gearing bc you stated it as if all of the newer trucks with this engine have 13000 lbs towing capability.

[@ML-lg4ky]

My truck gets 12 mpg and is cheaper per mile to own than these new “efficient “ trucks.

[@peiguy1982]

Europe has lighter diesel emissions requirements than North America.

[@Pickuptrucktalk]

No that’s not accurate.

[@NMTRUCKER]

Prove it.

[@peiguy1982]

@@Pickuptrucktalk "US federal emissions standards are broadly more ambitious for key local air quality pollutants, particularly NOx, than EU standards. A key difference is that the US applies a single set of standards to petrol and diesel vehicles, while the EU allows higher levels of air quality pollutants to diesel vehicles." Ever wonder why the VM Motori diesel was so robust and reliable in europe, and an absolute disaster in North America? I owned one for 52k miles and got off lucky with just a complete DEF system replacement. It's the nitrogen oxides that are so much more aggressive with in North America. Particulate they might be comparable. My understanding is the hotter the engine is running, which is when diesels runs best, the more NOx. The cooler you run them the trade off is more soot and particulate mess throughout the entire engine, but improves NOx. The GM particulate filter is under the hood, which is the rare exception AND might work better in North America with their TOUGHER NOx regulations compared to EU. It's the reason they put it under the hood last time I checked. Why else would you risk putting all that extra heat under the hood? I don't think it would work with HD trucks.

[@peiguy1982]

@@NMTRUCKER See the response to Tim. It's well known North America is more aggressive for NOx. Not sure why you two don't know.

[@mcjogom]

🎉👍👍👍👍🎉

[@ericconrad2383]

DEF and EGR is why I won’t buy a diesel

[@raylewis3355]

I have a 22 silverado with the lm2 not one issue with the truck. The DEF really isnt an issue either its about 20 dollars every few months.

[@down_yonder]

yep never again. over complicated choked out epa queens. just thinking about having to buy def all the time and spilling it all over the side of the truck again makes me cringe

[@BrianNC81]

I believe there are deletes available for lm2 trucks but it will void the warranty. Seen a few videos, they sound good straight piped.

[@dpg2826]

@@down_yonder Maybe you need an EV truck.. Then you won't spill any fuel either.

[@tnebbie3230]

Remove it

[@DaveInCanada081]

Inline 6 ☝️ DEF🫷NO!!

[@Pickuptrucktalk]

DEF is such a non issue.

[@birddogbriar4335]

​@Pickuptrucktalk I agree. Every 3000 miles or so I stop at tractor supply, grab a jug for $9 and top the tank off. Not a big deal or expense.