Advice on 2021 Tahoe, 5.3 V8 vs. Duramax 3.0

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MajorJakkov

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Diesel 3.0L all the way. Customers are willing to pay out the nose to have a company called DuraBurb graft a 2500 or 3500 truck chassis on to a 1500 truck body to get a 6.2 or 6.6L duramax diesel. Now you can finally get an I-6 3.0L turbo diesel that’s going to be completely tunable and get the 4-600k mi engine life that’ll pay you back through savings or resale.

My bug guy (exterminator) got one 6 Mo ago in a quad cab truck w/ 4WD and loves the 1-2x a Mo fill ups based upon where the lowest price fuel is. It’s like having a bulldog pulling your kids wagon who doesn’t know or care he’s doing it and wants the job just to spend time with you.

It’s on my radar until we wear out our 09 Platinum Esky ESV that’s loved for the e85 ($2.49 gal) fuel it sips @ 149k miles on the clock. Another member found a 3.0L Burb in SanDiego by dealer searching within just a few days. Find on, test drive it and be ready to ****** it after you drive it [emoji3]



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Just weighing in to say 2 things. One - diesels do cost a bit more to maintain ie oil changes (you REALLY have to keep up with them, especially with modern diesel engines equipped with an EGR), fuel filters, DEF, etc Two - in reference to the quote above, tuning GM diesels is extremely difficult. I'm not sure if it can even be done on the 3.0L but the current 6.6L L5P motor in the HD trucks took about 2.5 years to figure out and is quite expensive to tune (~$7k). I'm referring to tuning that allows the truck to operate at higher power and efficiency without plugging up that pesky DPF ;).
 

Stbentoak

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Just weighing in to say 2 things. One - diesels do cost a bit more to maintain ie oil changes (you REALLY have to keep up with them, especially with modern diesel engines equipped with an EGR), fuel filters, DEF, etc Two - in reference to the quote above, tuning GM diesels is extremely difficult. I'm not sure if it can even be done on the 3.0L but the current 6.6L L5P motor in the HD trucks took about 2.5 years to figure out and is quite expensive to tune (~$7k). I'm referring to tuning that allows the truck to operate at higher power and efficiency without plugging up that pesky DPF ;).

While you are correct on above items, this is nothing new and just daily fare for familiar diesel owners. 2 of 3 of mine get one oil change a year and the one we drive most gets 2 + 1 fuel filter change. Its neither difficult, nor excessively expensive....
Unless you don't care anything about warranty, there is no real reason to tune them. Sophisticated dealer software can detect ECM changes and your warranty is done. At least wait till out of warranty to mess with it....
 

1BADI5

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Don't know where you live but in most of my travels, Diesel is about 10-15 cents higher than RUL if that, and about 40-50 cents less than Premium... Where I am now in FL, RUL 2.86 Diesel 2.85 PUL 3.46

You can go appx 40% further on a gallon of diesel and premium is required for optimum performance of the 6.2.
I'm saying real world avg mpg for the V8 around town and some hwy miles per tank....17 MPG That might be generous unless your miles are mostly hwy instead of city...

I'm guessing real world mileage on the 3.0 for the Denali... 23 MPG per tank on average, as diesels usually surpass EPA estimates unlike gas estimates.

1000 miles on Diesel 47.5 gallons at 2.85 =135.37$
1000 miles on PUL 58 gallons at 3.46 =200.68$

At 15k mile per year avg that's about 980.00 a year in fuel. Most owners road trip and drive even more... Would certainly pay for your Auto insurance, and maybe your plates too...

Let's say gas get back up to 3.50 4.00 a gal for RUL ( is already there in some parts of the east coast and most all of CA...) Certainly conceivable as pandemic lays down and demand spikes for all fuels including jet fuel which had been basically dead...The spread widens and diesel desirability goes up further.

Bonus points also, for not having to fill up every week or every 6 hrs or so on a hwy trip. The Duramax is to me the #1 desirability factor in wanting this large SUV. Without it, would probably buy a GLS...

Wonderful, saved me from having to type all of that!

ONLY consideration............... MAKE sure you or the other drivers DO NOT put DEF into the diesel tank.

There is a lot of this happening right now and depending on the severity its either engine replacement or a very expensive repair bill. A lot of the associated 3.0 Duramax parts are on back order from 1-6 weeks right now.

Final note, there have been repeat customers that have dropped DEF into the diesel tank. Your insurance "may" cover the accident the first time, but the second time you'll be out of pocket. So please just pay attention to what you're doing.
 
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houseofdiesel

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IMO it comes down to preference and nothing to do with the gas prices. I love and prefer the range and power delivery of diesel compared to gas. Came to Gm from Ford due to GM offering multiple diesels throughout the lineup. Started with purchasing a 2016 Canyon 2.8L LWN diesel for my daughter's first ride. Absolutely love that little thing and have towed cattle and our deckover trailer with it often. Next we picked up a 2018 GMC Terrain with the LH7 1.6 diesel. Thing has been one of the most fun little commuter/beaters I've ever owned. Long trips with little luggage and daily driving is an absolute blast and the handling on it is equivalent to many sports crossover and SUV's that I've driven. As the daughter graduated from HS and now is in Ag/Large Animal Science at CSU she needed a larger truck capable of hauling larger loads and I ordered her a 2021 AT 1500 with the LM2. While waiting for it to come in, a dealership in Denver had one hit their lot when I was visiting and we swung over to get a test drive. I was so blown away that I ordered one for myself in the Elevation trim.

Since then my wife has fallen so in love with my truck that we sold her POS Expedition Platinum and until I can find her a 2021 Denali with the LM2 3.0 diesel I'm stuck back in the Terrain.

Is it 6.2L power absolutely not. I'd compare it to a 1st Gen Turbo Diesel tuned. As soon as tunes are available for these LM2 powered rigs they absolutely will however blow 6.2L away. They are extremely detuned for emissions. We have since towed all over the western US with them with zero issues. For daily commutes they are a blast to drive and there is zero need to WOT them like a 5.3L while towing or to merge. I've also driven the Ford and RAM variants and would say those are more Euro spec high rev diesel's while the power of the LM2 is more of the American diesel power delivery I'm used to from my HD diesels in my fleets and driveway.

So look at the option as more of a top option purchase than a comparison to the 5.3L savings. It will absolutely hold a higher value down the road in the thousands of dollars just like my Excursions have. You can get a 5.4L Excursion all day long for dirt cheap, while the 7.3L Excursions are bringing premiums close to or above original sticker price.
 

houseofdiesel

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Plus the fact that actual real world testing (Accelerated life tests..) has shown that this belt will easily go 200K. GM has actually thought about extending the 150K recommendation, but hasn't so far...

Its a non factor really, unless you drive like 50K a year etc....


Anyone that complains claiming pulling all the accessory drive apart is faster and easier than dropping a trans to change a timing belt or chain has obviously never turned a wrench in their life. I specifically will never buy another Ford product with the EcoJoke due to how much time it takes to change or work on the system. I drive close to 50k miles a year and it will take my mechanic a couple extra hours to replace that belt while doing a oil and filter service. I service all the trans fluids on my rigs at 150k anyways so not like I'll have an extra expense on fluids either.
 

Stbentoak

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Wonderful, saved me from having to type all of that!

ONLY consideration............... MAKE sure you or the other drivers DO NOT put DEF into the diesel tank.

There is a lot of this happening right now and depending on the severity its either engine replacement or a very expensive repair bill. A lot of the associated 3.0 Duramax parts are on back order from 1-6 weeks right now.

Final note, there have been repeat customers that have dropped DEF into the diesel tank. Your insurance "may" cover the accident the first time, but the second time you'll be out of pocket. So please just pay attention to what you're doing.

Well I've never made that mistake going on 10 + years now. But I'm sure others have done it. But I HAVE heard of many mistakes of using the gas nozzle and not paying attn. Will trash your engine in a New York minute. One good one in our town was a tanker dropped RUL in the diesel tank at a local station. They ate about 20 engines before someone figured it out. The fuel supplier paid the bill. Another one was someone put the green Diesel nozzle on the RUL dispenser line and some others didn't catch that too. The station paid for that one too!
 

1BADI5

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Well I've never made that mistake going on 10 + years now. But I'm sure others have done it. But I HAVE heard of many mistakes of using the gas nozzle and not paying attn. Will trash your engine in a New York minute. One good one in our town was a tanker dropped RUL in the diesel tank at a local station. They ate about 20 engines before someone figured it out. The fuel supplier paid the bill. Another one was someone put the green Diesel nozzle on the RUL dispenser line and some others didn't catch that too. The station paid for that one too!

Those were some expensive mistakes.

I follow a couple GM Master Certified techs, they have some wild stuff coming in.
 

sumnerblvd

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The consensus on the silverado/sierra forums is that the 3.0 has been great thus far. I really considered the 3.0 vs the 6.2 in the Denali, but we don't NEED the diesel, and for the cost difference per year, decided that I'd rather have the 6.2.
The
 

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