Well different stories for different cases, but in Subarus specifically, it seems even with 5k OCIs with "good" OTS synthetics, you can develop problems, at least in severe service.
Current top 0w-20’s?
- Thread starter 02s4audi
- Start date
My 21 Jeep Wrangler oil temps during normal driving range from 200f-215f. Which is acceptable for a 20 grade all day long. Off roading my oil temps reach almost 250f for hours which is no longer appropriate for a 20 grade. Not because the oil can’t handle the heat but because oil loses viscosity as it gets hotter and under hard use it’s a bad combination. So I use a good 30 grade.
Your oil temps could be normal depending on outside air temp and how hard you were pushing on the highway. The oil cooling for the 3.6 isn’t the greatest IMO. If you’re seeing these oil temps regularly(above 220f) I would go up in grade like you were planning. Some others in my group add oil coolers to help control temp.
This needs a repost button and a close thread
- Joined
- Jul 28, 2024
- Messages
- 1,630
lol. it is fascinating how one asks for a recommendation on top 0W20 oils and oil temperatures and 30WT must get thrown into the post.This needs a repost button and a close thread
0W-40!lol. it is fascinating how one asks for a recommendation on top 0W20 oils and oil temperatures and 30WT must get thrown into the post.
- Joined
- Jul 28, 2024
- Messages
- 1,630
that too.
You would do well to get off that train. You continually post about how certain engines carbon up their rings, making reference to oils that don't clean said rings as inferior.
Truth is, those are bad engines, that require specialized oil to keep their rings clean. This is not a knock against perfectly good oils that work great in 90% of the other engines on the planet.
Engines with carbon prone oil control rings are well served by oils like valvoline restore and protect. That doesn't mean that Warren oils are "inferior", minimum standard, and what ever other negative references you want to throw at them.
Last edited:
Well, they are "inferior" but only in the comparative, literal sense.
Most people hear "inferior" and assume "inadequate" or "inappropriate", which just isn't true. Many, many "inferior" oils will keep an engine quite healthy and happy a long, long time.
I blame GM!
- Joined
- Jul 28, 2024
- Messages
- 1,630
The thing that gets my goat is the failures aren’t oil related themselves but poor design and engineering
That failure IMHO was perhaps engineering (lousy drawing(?)) surface finish not properly specified, or failure to follow the specification. GM probably has been asking the "5 why's? I imagine.
The funny part about your criticism here is that you can't even complete the sentence without describing them as inferior yourself. Do you think that an oil that protects against CBU and cleans isn't superior to an oil that allows CBU? One is better than the other. One is "superior" and another "inferior." I guess we can get a participation trophy for Supertech for you. (The API donut.)
Sure, the engines described are more prone to coking rings. However, when you have one group of oils (boutiques, Euro spec'd oils) that prevent them from coking up with carbon and consequently they don't burn oil, and another group of oils that will coke them up, guess what, one group is superior to the other. I don't know why that is seemingly offensive to you. I'm sorry?
That isn't to say Warren oils are "bad." Compared to oils 40 years ago, they are boutiques. It's just a comparison, as Hohn describes well below.
I'll stay on the train as long as necessary.
But how do you know? I mean it's not like anyone can do much beyond squint at spec sheets, pick the best one and hope for the best.
Even oil analysis isn't a silver bullet. Most oils that are properly certified will do fine with mfgr recommended weights and intervals.
Let's face it - this is a hobbyist site at its core. It's just that rather than geeking about the relative merits of Nikon vs Canon or whether the Longhorns will win the title this fall, we're picking apart the minutiae of motor oils.
If there were clear differences or practices, they'd, you know, be clear. But the very fact that there's so much debate means there's precious little actual data one way or the other about oil weight and the rest.
I think you know from a combination of approvals, engine teardowns, and reported history here. For example, people who do well with certain oils in engines known to be hard on oils, well that's a good sign.
Agree on UOAs. There are people who have ended up with issues even with reassuring UOAs.
No arguments from me on this being a hobbyist site. 75% of us would be better off with an EV.
As our area's FTA and RCA specialist, this is in my wheelhouse.
I suspect it's likely not a design issue where GM suddenly decided to relax surface finish requirements after decades of knowing what works.
Far more likely IMHO is that a supplier with immature quality processes or people was never held correctly to the drawing requirements. The DQR was held, signed off, and they got through PPAP with parts that never met the actual drawing requirement.
There are lots of potential pitfalls with this. Perhaps a drawing was previously defined using Concentricity, and then since ASME y14.5 eliminated concentricity, they had to re-draw the drawing but with a runout spec and they didn't correctly translate the old concentricity into a new runout.
Maybe it was an old hand-drawing drawing and the Ra looked like an Rz.
A real quick story from the Cummins trenches on this one:
Over a decade ago, an engineering project was launched to dual source gears because the British supplier was maxed on capacity. A new chinese supplier was identified, the parts were PPAPd to the drawing. The project closed with an estimated $2.5m in value or so (IIRC).
About six months after it was first launched into production, we had a major geartrain failure at a prominent customer site. We'd never had geartrain issue before whatsoever.
Long story short, the British supplier had been fixing so many shortcomings in our hand-drawn, 1980s-vintage drawing that we had no idea our existing gears were far, far better than the drawing required in both metallurgy and geometry. The chinese supplier made the gears, they met the drawing and they failed catastrophically.
I think all told we spent $50m on customer issues tied to these gear failure. The mid-2010s was not a fun time to be in our large engine division. Komatsu and Hitachi were fit to be tied, and rightly so.
All this, with parts that "met the spec."
Lesson: you don't know what you don't know.
Assuming we are back talking about the 6.2 crank bearing failures...
Unless something has changed, PPAP is done when a part is qualified, but not again. The crank in question has a long history, I doubt it went through PPAP more than once.
And I doubt GM updated the drawing, eliminating specs, even if such omission was unintentional. And even if they did, the supplier won't change their build process because of said change. If they did, they would have to disclose the process changes to GM, submitting a new FAI, and their SQE's would have shot it down.
More likely, the crank supplier just got lax, and made a bunch of bad parts. The quality inspection people didn't realize these were bad parts, and the flow kept going. Poor process control during mfg, poor inspection procedures without enough specific detail regarding surface finish. Parts are not inspected to drawings, typically, there are inspection process documents, focusing on specific critical parameters. Which obviously were either not specific enough, or not properly followed.
What I'm getting at is that there are very few of us with the actual knowledge and experience to actually be able to gainsay the engineers who designed and built the engines.
And if there were actual differences between oil specs/weights/brands that were clear, it would be something that everyone would know, manufacturers would specify it, and everyone would move on. But as it stands, all that stuff is so murky that we've argued the same points for twenty some-odd years now, and without any actual resolutions.
To me, that means that all this stuff is very similar to "how many angels can fit on the head of a pin?" Interesting intellectually, but practically inconsequential. With the exception of engines with design or manufacturing flaws, we'll all be able to run them for hundreds of thousands of miles on whatever weights we want from whatever brands we want.
I think it’s easier to make an oil choice when you know if an engine is easy or hard on oil. Or if an engine series is known for sticking oil control rings. Things get much more complicated when purchasing a new vehicle without a track record yet.
I also find it interesting that most here agree lifetime transmission/cvt fluids are a bad idea but don’t question a manuals grade recommendation. My Jeep manual says lifetime transmission fluid yet the transmission manufacturer(ZF8) recommends 60k services. Jeep recommends 75W-85 front differential oil yet Dana recommends 75W-140. IMO some critical thinking is required.
I also find it interesting that most here agree lifetime transmission/cvt fluids are a bad idea but don’t question a manuals grade recommendation. My Jeep manual says lifetime transmission fluid yet the transmission manufacturer(ZF8) recommends 60k services. Jeep recommends 75W-85 front differential oil yet Dana recommends 75W-140. IMO some critical thinking is required.
Last edited:
I have had 5 3.6 pentastar engines and have never had an oil related issue..change at 3-5000 miles and use mopar filters and I used PUP 5w20 and the more recent ones PUP 0W20....I don't expect any issues...heck you could probably use a mix of butter and corn oil and if you changed it enough be ok...My good buddy worked for Mobil1 for many years and he said your engine actually does not care what oil you use.......
Perhaps their formulations contain butter and corn oil?
Similar threads
