6.7 Cummins vs 6.6 Duramax

[SoonerWing03]

As someone who knows next to nothing about Diesel engines, I am trying to figure out the strengths and weaknesses of these to. Any opinions would be appreciated.

[Groover]

Grit dog wrote:

SidecarFlip wrote:
I like them all so long as they smoke....

I'll drink to that! Roll coal brotha!

I sincerely hope that you too are joking. I was raised that when something I do offends others I needed to reconsider my ways, especially if that is the only reason for doing it.

[Turtle_n_Peeps]

Durb wrote:
Better torque characteristics

What does that mean?

[Grit_dog]

Here comes the fanboy stuff now.....
Soonerwing, either one will be comfortable, durable and have gobs of power. Period.

[FishOnOne]

Cummins12V98 wrote:


They sell the 6.7 to RAM but they also sell the same engine to others for Medium Duty applications. "True medium duty"

But the latest cummins uses the Bosch CP4.2 HPFP and now uses hydraulic lifters. Crickets...


Same goes for the Medium Duty AISIN transmission as it's used in many other MD applications.

Nissan Titan XD medium duty? Crickets...

Oh and Medium Duty Rams end up on Ford lots in various ways :B.... Crickets...

[ktmrfs]

both are very high quality reliable motors. IMHO don't let the engine decide your brand. Drive both and pick the one YOU like the best, not the one someone else likes. YOUR the one going to be using it.

[Cummins12V98]

Here is another thing to consider. What does CUMMINS do??? They build engines!

They sell the 6.7 to RAM but they also sell the same engine to others for Medium Duty applications. "True medium duty"

GM's D Max is used by what other Medium Duty Manufacturers? "Crickets"

Same goes for the Medium Duty AISIN transmission as it's used in many other MD applications.

"ALLISON" (GM Built), who else uses that trans for MD applications? "Crickets"

Well let's add another thing to chew on. Simply look around out on the Highways. What brand DOMINATES the "Independently Owned" RV and HotShot hauling market. RAM, there is simply no comparison.

Oh, they use them a lot to haul Fords. 😉

[memtb]

4x4ord wrote:

RCMAN46 wrote:
Longer stroke engines have higher piston speeds.

They do. And with only 6 cylinders that Cummins has to have much bigger, heavier pistons and rods flying around..... it's a wonder a 6 banger can even compete with a V8. 🙂

They also operate at lower engine rpms, which lowers the piston speed. Pretty much an irrelevant negative on the I-6!

Anyone questioning the reliability and power of the Cumins vs the V8’s should spend a few minutes watching (YouTube). the annual Diesel Power Challenge, held every year near Denver, Co. if you like “coal burners” you “WILL” be entertained and amazed!

[ACZL]

4x4ord wrote:

RCMAN46 wrote:
Longer stroke engines have higher piston speeds.

They do. And with only 6 cylinders that Cummins has to have much bigger, heavier pistons and rods flying around..... it's a wonder a 6 banger can even compete with a V8. 🙂

I love a V8 as well, but disagree with your last portion of your comment. Look at all the semis going down the road. Wether it's Detroit, Mack, Volvo, PACCAR or Cummins, they are all I6's. Shoot, look at what's out in the cropfields as well. Again, John Deere, Case, New Holland, they too are I6's

[4x4ord]

RCMAN46 wrote:
Longer stroke engines have higher piston speeds.

They do. And with only 6 cylinders that Cummins has to have much bigger, heavier pistons and rods flying around..... it's a wonder a 6 banger can even compete with a V8. 🙂

[2001400ex]

Lots of information and actual data here.

https://news.pickuptrucks.com/2018/07/whats-the-best-one-ton-heavy-duty-truck-for-2018.html

[Gulfcoast]

I grew up with Chevy's of every kind, that's all we would buy.... until I found a Cummins 5.9 diesel.

[Cummins12V98]

Simple, pop the hood on each. Class dismissed.

[_1Flyboy]

The Duramax is an Isuzu designed motor with the Allison transmission; I believe 2019 is gonna be the last year one can get a TRUE Allison 6 speed; they’re going to a Allison “branded” 10 speed for 2020....Hard to go wrong with the Duramax Allison combination.... Cummins motor is on par with the Duramax, but, not sure about the attached transmission.... I don’t think you will be disappointed with either....

[RCMAN46]

Longer stroke engines have higher piston speeds.

[4x4ord]

azdryheat wrote:
My Duramax is quicker off the line than my friends Cummins.

My wife's Honda Civic is quicker off the line than my Powerstroke but I don't think I have ever pushed the skinny pedal all the way down without a trailer on behind and a big hill up ahead.