Beware of the new Cummins 6.7

CGiron

New Member
Dec 11, 2018
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Let´s guess about the power numbers now. The engines are in production and will be revealed in four weeks. 
 
I think 990 lb/ft of torque and 450 hp in the Ram 2500
 

Green_mtnMan

New Member
Dec 4, 2018
5
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3
Do you think 2018 HD truck prices will drop much after January, or only toward the end of the year when 4.5's actually are rolled out en masse?
 

Green_mtnMan

New Member
Dec 4, 2018
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Though I very much want to buy a 2018 diesel dually right now, the potentiality of a x 3-ish MPG bump would be a tremendous boon for me w/ the new engine / 8spd transmission. If it turns out that there is not a significant bump in efficiency, I'll probably just go with a 4.10 2018 Aisin transmission w/ the old 6spd automatic... I'm just looking for a rig that will haul around a 25K trailer with the least amt of diesel, lol...
 
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CGiron

New Member
Dec 11, 2018
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6
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Strange move to exclude the new Cummins with 1000 lb/ft for all but the 3500. Reason?
Are they trying to make the 2500 buyers to move to 3500?
 

Admin

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Nov 16, 2018
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Strange move to exclude the new Cummins with 1000 lb/ft for all but the 3500. Reason?
Are they trying to make the 2500 buyers to move to 3500?
I had a feeling that is how it would be. Previously they offered the Cummins in 2 different power levels restricting the HO to the 3500 as well. Honestly I think they should just offer the HO across the board as the only diesel option. The other manufacturers only offer 1 diesel option, both more powerful and with more torque than the standard output Cummins.
 
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DevilDodge

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Nov 21, 2018
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You have to give something to the Heavy HD guys.

It used to be the transmission. Maybe they can't put the Aisin trans into the 2500 for payload reasons or the such. Just offering a reason. The old system went low out put forthe G56, 800 for the 6speed auto and 850 for the Aisin.

I actually thought the years before the Aisin you got the HO in 2500 and not in the 3500.

Will have to check.
 

1HasBeen

Member
Jan 20, 2019
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I am pretty happy with the power and torque numbers, but I am very disappointed they went from the reliable CP3 injector pump to the infamous CP4.
 

1HasBeen

Member
Jan 20, 2019
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What is the CP4 Issue?
Just google CP4 failure and you can read for days. So, the CP3 that Cummins has run since common rail came out in '03 is very reliable, and if it does fail it just quits and you change it out. Ford and GM have been running the CP4, and it does not do well with the ULSD fuel in the US, it is much, much, much more sensitive to fuel quality issues, and due to the basic design, when a CP4 fails it makes shrapnel that ruins the lines, the rails, the injectors, the relief valves, the rail pressure sensors, etc. So basically it ruins the entire fuel system. GM finally got away from it and went to a Denso system. Ford offers a kit to convert to a CP3. What does that tell you??? Now there are rumors of Ford getting away from the CP4, too.

There is talk that it has been internally improved, but I have seen nothong to confirm it. The fact that it says CP4.2 does not mean it is a unit revision. Plus, and most importantly, I have seen nothing that leads me to think it is even possible to prevent it from ruining the rest of the fuel system in the event of a failure.

I wish Ram and/or Cummins would address this directly. They are not fooling anybody. People who have been around these motors are well aware of the CP4's terrible reputation in the industry. They are risking a HUGE black eye in the name of a cheaper component.
 
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Admin

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I forgot to update this post. So we talked to Ram engineers at the media event and the Cummins does not use the CP4 injection pump as people have been speculating. They are using an RP6 injection pump which unfortunately I haven't been able to dig any information up on yet. I do plan on writing an article about it when Im finally able to track down more information on the pump.
 
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1HasBeen

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Jan 20, 2019
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Forgive me, but the information put forth stated CP4.2, and that is not speculation. Here is the lead engineer at Cummins clearly stating it in this video:
 
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Admin

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hdrams.com
Forgive me, but the information put forth stated CP4.2, and that is not speculation. Here is the lead engineer at Cummins clearly stating it in this video:
Weird I just watched that for the first time and yeah he does say it's a CP4.2. We asked an engineer at the Ram event why they went to the CP4 and were told that it isn't a CP4 but an RP6. I have even confirmed that since the event.

That said the fact that I can't find a single thing on it, combined with what is said in that video leads me to believe that it is the CP4.
 

1HasBeen

Member
Jan 20, 2019
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Some of the videos that highlight new components have shown what looks like a CP4 sitting there. I spoke with a couple Cummins people, and a Ram rep at a trade show who also said CP4. They also apparently use it on the V-8 Cummins in the Nissan, but the volume is so low it is hard to draw any conclusion from that unit.
 
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jeff

New Member
Mar 7, 2019
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So the CP4.2 is used in the HO engine, but is it used in the non HO Cummins engine?