DD16 vs 6NZ

If you plan on trading every couple hundred thousand then go with the engine you think you'll like best since you won't have it very long anyway. IF you plan on keeping it long term get the 6NZ, they have good power(especially with a god tune)and don't have all that EPA crap to cause problems.

 

had a 6nz tune by haney and have a 14 liter tuned by leon the detroit will run all over the cat

 

If two engines are rated at 550 they should pull exactly the same. But the reality is engines aren't rated perfectly.

 

While true to some extent, remember the pre-emission Cats had a nice hump in the HP curve. The 550's were rated@1800, but made almost 600hp @1600. IIRC the Cummins had a hump, too, just not as pronounced, while the Detroit had a more linear shape to the curve.

So at anything other than rated rpm, Cats made more power than equivalently rated engines.

 

It's not the horsepower....it's all about the torque curve.

 

For what it's worth.....if you are replacing your truck that often, isn't it a pain having gliders built and getting ownerships for them? They seem to be easier to get in the U.S. than here in Ontario Canada, but still.....is it worth it if you are trading before most warranties are up?

And if it helps your decision....I have the DD15 in my 2013 Western Star. I did have problems with my DEF system freezing and derating me in the winter....until I found out I had a bad air dryer. This last winter not one issue after it was replaced. But other than that I haven't had a single issue with that motor. Not one check engine light or fault code.
Now if I am working in the city with light loads like hauling snow in the winter, it will want a parked regen every 8 hours. But if I am driving on the highway, it does it all on it's own. And it doesn't use a lot of DEF fluid.

It has been a FAR more reliable engine than out ISX Cummins.

 

I wanted a glider, but here in Ontario they changed it. I used to be able to get a Star rolling glider, but now you have to have an ownership from a currently registered donor truck that you own.

Next truck I am getting a DD16, but this last 2013 we went with the DD15 505 at the time for a couple reasons. A couple Detroit reps I spoke with at a truck show agreed with my thinking that a smaller motor working harder would be better for the DPF. And the 7 year extended warranty was 5 grand cheaper then if we went 560/1850.
And I spend a greater percentage of time running 80,000 pounds as a straight dump truck then I do pulling 140,000 with my pony trailer.
But I'm going to try the DD16 now just to have the extra grunt with the pony in the winter.

But even the 505/1650......with my pony on grossing 140,000, running with out ISX600/1850 Coronado 122SD....same gearing and tire size, I can stay side by side, even pass it at the start of the 10 and 12% grades until I get down to the low range of the transmission (fourth gear) it will walk away from me. But from a standing start it can't chase me down on flat ground.
I drop down to 5MPH slower than that ISX on the same hills.
Engine brakes....almost equal, but the Cummins has a very slight edge.