Which dually - 8.1 vs pre-DEF 6.6?

[Frankenchevy]

Looking for a crew cab dually. As a dedicated dump trailer/equipment trailer vehicle. I read that 06-07 dmaxs are the least problematic. Also read that 03-05 are fine once original injectors are replaced. 8.1 is obviously more simple, but lower fuel economy I’m guessing…and less torque. Which way would you go?

Here’s the dmax. 131k and the won’t budge on the price ($17k). Injectors and turbo replaced at 80k. Leather trim level and clean interior.

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Here’s the 8.1. 122k and second owner since it was a year old. Has the common ABS module issue. Just have to open it up and resolder a couple pins. Cloth interior, but pretty clean. They said they’d take $12k right out of the gate.

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[carfanatic63]

8.1 all day.

 

[bluex]

Honestly if it primary purpose is towing anything over 10k lbs the diesel in a better buy.

 

[Frankenchevy]

8.1 all day.

I just read that 8.1s all consume oil. Is this your experience.

Honestly if it primary purpose is towing anything over 10k lbs the diesel in a better buy.

For longevity’s sake or fuel consumption?

 

[bluex]

For longevity’s sake or fuel consumption?

Just because that's what they are for an are much better at it.

I used to be solidly in the "why does everyone need a big diesel truck" camp. Gas trucks do it just fine. I started towing heavier stuff an it started to make more sense. My gas truck does it sure but it struggles on hills (I'm on the edge of the mountains), gets horrible mileage even empty an just overall feels rougher on the truck. The diesel seems to do it more effortlessly, gets better mileage loaded or unloaded etc.

I don't want another/different truck so it's getting a cummins soon but if I was looking at purchasing something that comes with a decent diesel already (ie not a 6.2/6.5 ) then I wouldn't consider a gasser for a primary towing vehicle. If it was only gonna tow 3-4 times a year then maybe since the cheaper maintenance might be able to offset the fuel mileage.

From your description it sounds like it'll spend more time with a trailer on it than off so that's a no brainer for the diesel in my book.

 

[Frankenchevy]

I have no experience with a modern BBC, so I am not at all aware of their towing characteristics. I am a Cummins guy when it comes to diesels, but I don’t want anything newer than 07. My buddy just dumped $10k into his modern diesel with 100k on the clock. Seemingly minor stuff too. We have a newer Cummins as well, but pretty low hours and mileage.

I’d be open to a dually automatic version of my 04 Cummins or a dually automatic 7.3, but they are considerably more expensive in similar condition. I feel like older people gravitate more towards the IFS of the GM products and you can find them in nice condition for a reasonable price more often. A 130k 04 Cummins as nice as that duramax would be double the price.

 

[legopnuematic]

I don't have any experience with a Duramax personally, but some with an 8.1/6 speed. Not a race truck by any means but pulled good.

Not sure what the mileage was like but I'd imagine high singles low doubles loaded.

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Don't have a picture of it when it was pulling it but that same GMC hauled this dump bed, think it was like 24k lbs total, between truck, trailer, and dump box.

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And there is the legendary 8.1/6 speed truck, over 500k on it and continuing to haul junk around

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Not to say the 8.1 is better than a Duramax, or the other way around, I think both are very capable.

Duramax definitely has some PITA things about it, stuff like the water pump and turbo access, compared to the Cummins platform at least.