Looking at a 2026 GMC 1500 Diesel which I guess is the upgrade LZO engine.

Does anyone have any experience with this truck and diesel engine?

I don't have one but everyone i know that does loves them. It would be my first choice in gm 1500. I'm tempted to get one.

from the little research I did, if you do a lot of highway driving then diesel. But if most of your mileage is just average around town then the fuel and maintenance price basically offset any savings you get on mpg.

I was next to a 1/2 ton Duramax the other day in traffic. I swear it auto start/stop. I didn't think the diesels had to have that.

It's a cheaper option than the 6.2 still. Be aware of the thrust bearing failure on 25s and early 26s, required full engine replacement if you are looking at used. Even with the engine replacement at 6k miles, we still love our suburban with the LZO. 30 mpg highway, 16-18 city. Tows so smoothly.

mwlkr said:

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Hardcore Greg said:

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Tree Hugger said:

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I like the idea, but with diesel over $5/gallon I would have to research the fuel economy vs. a gas engine to see if there is a benefit. I've never had a diesel that wasn't a rental, but I'm lead to believe that maintenance costs are bit more as far as oil changes though I'm not sure of the delta compared to a gas engine.

Long story short, diesel is expensive and I know very little about the other metrics.

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And don't forget that a diesel is like $10k more than gas truck off the lot. It's almost impossible to recoup the mpg differential when you consider (a) how much pricier the engine is and (b) how much more expensive diesel is at the pump.

That being said, if I was made of money and wife was cool with me getting a $90k truck, I'd get diesel in a heartbeat.

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Option price of the 3.0 Duramax is $2,390.00.

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Ah dang, not bad. Guess I was assuming the 3/4 ton variance between diesel and gas applied to 1/2 ton.

Be prepared for electrical gremlins. The engine is fine.

I have the LZO and have 70k miles on the truck and love it. Pulls anything I've asked it to. Auto start stop eliminator for the win. Took 5 minutes to install.

1939 said:

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Silvy said:

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305 hp doesn't sound very enticing

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305 is more than fine in a diesel with high torque.

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If you're trying to pull away from a light with a trailer, sure. If you're trying to move quickly, no.

I've done it pulling a Cat 262 skid steer.What did I do wrong?

Isn't that the smallest thing Cat makes

21 gmc with the 3.0 162k. Has been great. It's the wife's truck, so that maybe a harder life than normal wear and tear. Oil and filter every 5k. Fuel filter every 10k.

It moves fine for a truck, it's not a race car. It has pulled a too heavy for it equipment trailer with busted 8 speeds and busted 6.2L's on the trailer multiple times, no issues. Then gets 23 mpg without the trailer.

Not going to justify the cost by MPGs. But will justify it if your 8 speed dies. Or your 6.2 lifters do what they do.

Don't get me wrong. I love GM pushrod V8, but not buying the AFM stuff.

Edit: live update picture

Hardcore Greg said:

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Tree Hugger said:

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I like the idea, but with diesel over $5/gallon I would have to research the fuel economy vs. a gas engine to see if there is a benefit. I've never had a diesel that wasn't a rental, but I'm lead to believe that maintenance costs are bit more as far as oil changes though I'm not sure of the delta compared to a gas engine.

Long story short, diesel is expensive and I know very little about the other metrics.

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And don't forget that a diesel is like $10k more than gas truck off the lot. It's almost impossible to recoup the mpg differential when you consider (a) how much pricier the engine is and (b) how much more expensive diesel is at the pump.

That being said, if I was made of money and wife was cool with me getting a $90k truck, I'd get diesel in a heartbeat.

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Maybe for the HD models, but the 2 1500s I've got weren't any more than the gas.
I know these are Chevy, but same packages, same everything.

Duramax: https://www.resslerchevy.com/inventory/new-2026-chevrolet-silverado-1500-rst-four-wheel-drive-crew-cab-3gcukee82tg472417/

5.3 gas: https://www.resslerchevy.com/inventory/new-2026-chevrolet-silverado-1500-rst-four-wheel-drive-crew-cab-3gcukeed4tg484792/


Basically the same price.



My 2025 has been getting phenomenal mileage lately. Got 625 miles out of a tank, 26+ mpg mixed driving.