Right it's still 40 grade recommendation
Cummins 6.7L general questions
- Thread starter Fishstyx
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- Dec 30, 2022
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That Doesn’t mean Cummins doesn’t want to do what they can to make big daddy fed happy.
The 15w-40 is the standard fare in the GM 6.6L V8 Duramax diesel and an option in the Ford 6.7L Powerstroke, but with the hydraulic lifters in 2019+ Cummins specifically says not to run the 15w-40 oil.
It gets below 0 degrees for just 3 months? Remember, the Cummins via the owners manual is talking about 0°F here, not °C which is 32°F. It might get cold enough to snow or even get below freezing for a few days at a time here in Texas, but it doesn't get below 0°F.
I haven't decided yet which oil viscosity to use when I get to the my first oil change on my new MY23 Ram 2500 Cummins. Coming from GM I believe their 0w-20 viscosities were heavily influenced by the EPA and hated to use it on my 6.2L V8 when 5w-30 and then 0w-40 are what they are calling for on the same long block in other vehicles like Camaro and Corvette.
An interesting thing that I wanted to share and get other's here's opinions is on the Shell Rotella T6 10w-30. Although recently released, it's still hard to get but you can order it on Amazon for reasonable prices. But it's product specs are what prompted me to clarify with Shell whether or not they were indeed correct. Shell is saying that their Rotella T6 10w-30 has a 14.7 cSt at 100°C kinematic viscosity which places it in the 40 weight oil category, not the 30 weight that the rating on the bottle says. Most other CK-4 10w-30's are running between 11.0 and 12.1cSt at 100°C.
The Shell Rotella T6 5w-40 only has a 14.9 cSt kinematic viscosity at 100°C for comparison's sake. Given that, the oil viscosities appear to be nearly identical, but I do like the 5w-40's -51°C pour point a lot better than the 10w-30's -39°C, not to mention that the Shell Rotella T6 5w-40 is widely available and even less expensive.
Another interesting tidbit is that while the owner's manual specifically mentions the Shell Rotella by name, Cummins officially endorses Valvoline, (kind of like the way Mobil1 is endorsed by Corvette.) So if Ram and Cummins are using Rotella T6 10w-30 as factory fill, they're essentially using a 40 weight oil by spec and that is in part what makes me so unsure as to which direction to go. If a high 14 cSt is indeed what Cummins prefers, I'd rather go with the 5w-40 Rotella T6 with it's -51°C pour point.
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You bring up some good questions.
Before you pull the trigger, I suggest searching youtube for the Diesel podcast and watch the episode titled "Don't buy this truck...they messed up". Apparently there are some recent issues with Cummins, especially when the engines are tuned.
I don’t want to “tune” or delete it so that doesn’t concern me. There’s a major problem with the cold air intake which has the air heater at a nut can fall off on go right into tge valve train or cylinder. There’s a fix to it from Banks.
Do yourself a favor and watch the podcast on youtube starting at 46:40. It addresses some issues with (I believe) the current gen 6.7 engines in stock configuration. I listened to the entire podcast a few days ago, and it was very informative, even though I have a BMW diesel instead of a Cummins.
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Mostly because box tunes aren’t setup properly or they haven’t done other supporting mods to gain most from tune I believe.
That guy sells engines, I'm going wait on what he says about the block until I see further proof. Any block can frett when pushed hard, when its common you hear about it.
just buy 5W40 CK4 oil that carries the CES 20086 certification and all the rest is just noise..
the engine will outlast the rest of the truck.
its also worth saying if you have to operate that vehicle in -50C temperatures, the oil viscosity is only going to be a minor concern.
You certainly don't get any advantage when you are comparing the Rotella T6 products, 5w-40 vs 10w-30.
I agree, I like the better protection of a 40-weight oil (over that of another 10w-30 say from Valvoline,) and it can be acquired much easier than the 10w-30.
The factory grid heater is indeed a weak point on the 6.7 Cummins, but there are relatively viable solutions from Banks and others, although Banks may be the only ones who has a replacement heater with their kit. I wouldn't "not buy" a 6.7 Cummins for that issue, alone.
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Thanks for all your help and good advice
yeah, the 10w30 diesel engine oils are still relatively new to the market, so the choices seem more limited than the 5w40 choices, and the pricing seems to be similar between the two.
I've heard of the grid heater bolt failure, but never saw it happen in practice..
then again, operating in southern Florida we don't get much of the Wait to Start routine either.
Fleetguard LF16035, Donaldson Blue DBL7349, and the Fleetguard LF9028 which has built in bypass but they’re not cheap.
I run the Donaldson Blue filters myself on my HO Cummins 3500 with HPL 5w40.
I usually buy ten at a time from Rock Auto... 5 year supply.. currently have some wholesaler closeout US made filters I paid $1.30 each for. when I use them up whatever the next deal is will go on the shelf in the garage. .
One thing these Cummins engine's aren't is delicate.the B series starts out life in the 80's as a tractor engine, a joint venture between Case and Cummins known as the Consolidated Diesel Corporation. Somewhere along the way Cummins bought out Case Tractors side of it , in the late 80's the 6BT as it was known got shoved in a OBS Dodge Ram and the rest is history.
