3.0 Duramax opinions/experience??

Flyjunky

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Jun 22, 2020
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Like the title says, anyone have any good or bad things to say about the 3.0 Duramax in either the chevy or gmc platform?

I like the specs on paper but I don't know anyone who has one to get some real firsthand experience. I have a feeling the truck market might come back down to earth in a while and I want to be ready when it does.
 

tdhanses

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Sep 26, 2018
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Love mine, have a 2021 GMC SLT with 25k on it. No major issues, have towed 12k behind it on accident when my dump trailer was overloaded getting gravel, pulled it like a champ but wouldn’t recommend.

City driving I avg 23mpg hand calculated and hwy i’ve gotten over 30mpg for 400+ miles.

Hardly uses def when not towing, about 5k between fill ups and I’ve only gotten def at the truck stop pumps, when towing it sucks the def.

I would say avg towing mpg is 14-15mpg. The computer for mpg is always lower then hand calculated.

It has a soft cushy ride from the factory but I put a Rough Country 3.5” lift on it and now it sits close to 3/4 ton ride height and the factory tires look perfect so no need to get new rubber, ride is now stiffer but still smooth.

I have Timbrens on it for towing to reduce sag but think airbags would be better.

I really wish they would put this motor and trans in a 3/4ton, it’s the perfect setup for towing and efficiency.

In the mountains it does better then my 2019 F250 6.0 gas did towing.

It’s not an off the line drag racer but has plenty of get up to pass when needed even when towing.

I’d highly recommend it.
 
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Ucsdryder

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Jan 24, 2015
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He pretty much nailed it all. I can pull 26 driving city if I baby it. I freaking love mine, minus the extra dollar a gallon for diesel. Which really pisses me off because diesel should be cheaper to refine than gas!
 

c670809

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Jun 13, 2013
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Location
Reno, NV
I don't own one so please keep that in mind. I was considering buying one but the new design uses a belt driven oil pump. The belt is supposed to be changed at 150,000 miles and the transmission must be pulled to do that. I was not able to find what the cost would be. People were throwing around $3000. I don't know if that is correct but the design decision made me decide it was not for me.
 

tdhanses

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Sep 26, 2018
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I don't own one so please keep that in mind. I was considering buying one but the new design uses a belt driven oil pump. The belt is supposed to be changed at 150,000 miles and the transmission must be pulled to do that. I was not able to find what the cost would be. People were throwing around $3000. I don't know if that is correct but the design decision made me decide it was not for me.
So after 10-13 years you have a maintenance item, doubt cost will be that high but even if it is, that’s less then $300 a year based on ownership, we’ll know more with time as some already have over 100k on their trucks.

The belt isn’t a concern imo.
 
OP
Flyjunky

Flyjunky

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Jun 22, 2020
Messages
1,305
Love mine, have a 2021 GMC SLT with 25k on it. No major issues, have towed 12k behind it on accident when my dump trailer was overloaded getting gravel, pulled it like a champ but wouldn’t recommend.

City driving I avg 23mpg hand calculated and hwy i’ve gotten over 30mpg for 400+ miles.

Hardly uses def when not towing, about 5k between fill ups and I’ve only gotten def at the truck stop pumps, when towing it sucks the def.

I would say avg towing mpg is 14-15mpg. The computer for mpg is always lower then hand calculated.

It has a soft cushy ride from the factory but I put a Rough Country 3.5” lift on it and now it sits close to 3/4 ton ride height and the factory tires look perfect so no need to get new rubber, ride is now stiffer but still smooth.

I have Timbrens on it for towing to reduce sag but think airbags would be better.

I really wish they would put this motor and trans in a 3/4ton, it’s the perfect setup for towing and efficiency.

In the mountains it does better then my 2019 F250 6.0 gas did towing.

It’s not an off the line drag racer but has plenty of get up to pass when needed even when towing.

I’d highly recommend it.
That's exactly what I wanted to hear. I would lift it as well so it's good to know it didn't affect mileage too much.

Is there any reason, besides options, to go with the gmc vs chevy?
 
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Flyjunky

Flyjunky

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Jun 22, 2020
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He pretty much nailed it all. I can pull 26 driving city if I baby it. I freaking love mine, minus the extra dollar a gallon for diesel. Which really pisses me off because diesel should be cheaper to refine than gas!
I know, that makes my dad upset as well. Bottom of the barrel gas is more expensive than regular, I don't get it.
 
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Flyjunky

Flyjunky

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Joined
Jun 22, 2020
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1,305
I don't own one so please keep that in mind. I was considering buying one but the new design uses a belt driven oil pump. The belt is supposed to be changed at 150,000 miles and the transmission must be pulled to do that. I was not able to find what the cost would be. People were throwing around $3000. I don't know if that is correct but the design decision made me decide it was not for me.
From what I've been able to research it does sound like a pain but I'd be willing to deal with it down the road when it comes time.
 

tdhanses

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Sep 26, 2018
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That's exactly what I wanted to hear. I would lift it as well so it's good to know it didn't affect mileage too much.

Is there any reason, besides options, to go with the gmc vs chevy?
I don’t think mileage is really affected unless you put on bigger heavier tires.

I prefer the look of the GMC, other then that I think they have trims that have similar options.
 
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