What weight oil are you running

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1Nighttrain

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2006
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I’m planning on purchasing a 2024 6.7 that calls for 10w30 or 5w40

What weight are you using in your truck ?

I’m upgrading from my 2006 I used 15w40
 

06 Dodge

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Forest Grove, Oregon/soon Osage Iowa
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2022
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6.7L CTD
I’m planning on purchasing a 2024 6.7 that calls for 10w30 or 5w40

What weight are you using in your truck ?

I’m upgrading from my 2006 I used 15w40
I run 5w40 year round in my 2022 6.7, I've been using that weight since 2006 including my old Cummins 5.9l, also a good number of hot shot truck owners also use 5w40 year round in there 2025 & 2026 6.7...
 

Burla

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2010 Hemi Reg Cab 4x4
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Hemi
Upgrading? You should never got rid of that 5.9 with all due respect. If you still have it, I'd never let it go. Now you have external EGR, DPF diaper on the tailpipe, and def.

Despite the USA woke war on engine oil where manu's face huge fines for not doing what they are told by blue haired freaks running the EPA at the time = FCA changed the recommended oil spec on the eco diesel from 30 weight to 40 weight. Something you never see manu's challenging the govt and going against their wishes facing huge backlashes. This change was made to address bottom-end bearing failures and to provide a stronger oil film to protect the crankshaft during low-RPM lugging. In other words so many engines were failing from thin oil they said we literally have to use thicker oil in the diesel period stop. Now they simply discontinued the eco diesel, it was literally like watching blue hair policy ruin a truck before your own eyes.

They not only made oils thinner, they made them low saps. Sadly, you cant opt out because they also destroyed longevity in engines with EGR cooler design, so if you opt out of blue hair policy on that, it will bite you. So you cant use heavy additives oils like you had 20 years ago or your filters will gum up. You also should be careful/mindful on how you drive. Short trips arent recommended, hopefully you have a second vehicle as a grocery getter, plus use a good cetane boost for more complete combustion, look at Cummins recommended one under warranty, only use power service diesel Kleen.

Sorry to be gloom but there was a total assault on diesel tech and we lost. Inmates are running the asylum. Thanks to all of this owning a diesel is advanced ownership, you need to plug in and be Jonny on the spot on maintenance and never shrug what needs to be done. By the time you even get a CEL you likely have a gummed up machine. The good news is you have that ten year warranty, so be grateful for that. You machine likes long trips, that can correct some of the damage being done with short trips.

long story short, diesels were never meant to have 30 weight as an option, the compression ratio is 16:1 whereas hemi's 10:1. Lot's of pressure and 30 weight isn't enough. Very similar to hurricane compression ratios at the end of stroke. People running 20 weight in a hurricane will work as good as 30 weight worked for the eco diesel, story yet to be told on that one. RAM spec'd 0w20 in a SO but 0w40 in an HO, lol? I guess as long as they have a ten year warranty, never mind, but I'd follow maintenance on those as well. Your spec options are political, I say opt out. It's your machine now not the epa's.
 

Burla

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I’m planning on purchasing a 2024 6.7 that calls for 10w30 or 5w40

What weight are you using in your truck ?

I’m upgrading from my 2006 I used 15w40
if you still have that 5.9 watch this... 2006 a very good year new cp3

 

stevenP

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I also use 5w40, T6 rotella synthetic. Mine is a 22, so they changed the engines internals (lifters) so you cannot use 15w40 anymore. Not sure on a 24, so consult the manual.
 

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