6.0vs6.6, 6.2vs7.3, 6.4 Hemi

   #21  

nikerret

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Have a a 6.2 engine with the 10 speed tranny in my 2020 Yukon and love it.21-22 mpg,s highway 18 mpg,s city/highway.

The GM 6.2L, in the Yukon is not an engine available in a 3/4 ton.
 
   #22  

coobie

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The GM 6.2L, in the Yukon is not an engine available in a 3/4 ton.
I wonder why not? 420 hp with 10 speed IMHO is the sweet spot.
 
   #24  

Lineman North Florida

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I wonder why not? 420 hp with 10 speed IMHO is the sweet spot.
My wife has a 6.2 in her Yukon and I wondered the same thing, so I asked a GM mechanic, and he told me that those engines were like comparing apples and oranges, he said the 6.2 would never hold up to regular heavy towing like the old cast iron block GM 6.0 , my wifes 6.2 has been flawless but it only pulls itself, I wonder if the new 6.6 gas motor has Active Fuel Management? I sure hope not.
 
   #26  

WilliamBos

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My wife has a 6.2 in her Yukon and I wondered the same thing, so I asked a GM mechanic, and he told me that those engines were like comparing apples and oranges, he said the 6.2 would never hold up to regular heavy towing like the old cast iron block GM 6.0 , my wifes 6.2 has been flawless but it only pulls itself, I wonder if the new 6.6 gas motor has Active Fuel Management? I sure hope not.
No AFM/DFM or start/stop.


 
   #27  

LD1

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If you look hard enough on the internet, you will find good opinions and bad opinions for all of those engines and each of the big 3 brands.

At the end of the day, they all have their pros and cons....and cost of ownership over the lifetime of the vehicle is likely gonna be similar no matter what route you take. I have found that vehicle reliability/durability is more a function of who is driving and how its taken care of rather than the name on the front and the engine under the hood.

One thing is for sure....all the modern 3/4 tons are quite capable trucks, even with gassers. And any combination you choose will likely serve you very well. For me, my decision wouldnt come down to whats under the hood or what name is on the truck. But rather what I like, driving, handling, ergonomics, options, and price.
 
   #28  

nikerret

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I wonder why not? 420 hp with 10 speed IMHO is the sweet spot.

It is a light duty engine, it is not designed for heavy duty work. The new 6.6 gasser has 401 HP/464 torque.

WilliamBos beat me. The short version is the GM 6.6L is made to make its power all day, each day, at a lower performance per dollar cost versus the GM 6.2L light duty engine.


The GM 6.2L is designed to get higher horsepower numbers at higher RPM, at a higher compression ratio. The GM 6.6L has a lower compression ratio and uses 87 octane, instead of the Premium fuel the GM 6.2L uses.

In this case, we are comparing the L87 (6.2L light duty engine) versus the L8T (6.6L HD engine).

Here are some key differences:
Detail - L87(6.2L) - L8T(6.6L)
Compression - 11.5:1 - 10.8:1
Block - Aluminum - Iron
Fuel - Premium - 87 octane
Cylinder Deactivation - Yes - No
Redline - 6,000 - 5,600

The big difference between the L87 and the previous GM 6.2L L86 is Dynamic Fuel Nanagement versus the previous Active Fuel Management.
 
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   #29  

nikerret

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Well, I accidentally hit post, but wasn’t done.

Here is a factory dyno graph of the GM 6.2L L86 (looks the same as the L87):

FBA8987C-8093-434F-94F1-7E70587ED74B.jpeg


All you could want to read on the L86/87:


Here is the factory dyno graph for the GM 6.6L L8T:

FAF97566-3EBE-4406-A9B1-CEEF13D9A44E.jpeg



All you could want to read on the L8T:

An article comparing the two:


Notice how the L8T/6.6L makes more torque at lower RPM versus the L87/6.2L that does make more power, overall, but takes more RPM to make the same power, in the lower ranges.

Under the same conditions, the L8T will outlast the L87 due to having an iron block, lower compression ratio, a regular pushrod (no DFM), and being able to do more work at a lower RPM. And it will do it on less expensive fuel.
 
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   #30  

WilliamBos

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Which 6.2L and why ?


In my original post I was refering to the Ford 6.2, I will not own one, not a fan of their Triton engines In a HD application. I would take an F250 7.3 Godzilla in a heartbeat.

In a truck application, I will never own a GM 6.2, no need nor use for a truck engine that requires premium fuel, especially at $5.96 a gallon.
 
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