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I ran 20w40 conventional in my ski cars for years with cold starts around 0 f often. These Subarus called for 5w30 mostly. All ran past 200k (one 300k) before I sold them, one blew the engine at 250k- thrown rod....
Benefits of 0W
- Thread starter Trackspec
- Start date
That’s not advisable.
I think FS 0W-40 was at 12.9 for a long time, no? Now it's 13.8 so I would imagine that would lengthen the amount of time/wear that the current formulation would need to drop to a 30.
Not that all oils in a grade directly represent the nominal, but...
That 20w-40 was about 10.8k cST at 0 deg F. A nominal 5w-30 would have been there at -33f. You were essentially starting those motors at -33f.
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Plus the issue isn’t really about cranking, that can be mitigated a bit with a good battery.
I think the oil pump drag's impact (due to thick oil) on starting speed is often overplayed, so you and I are on the same page. That pesky T in the arrhenius equation. Battery performance drops fast enough IMO to be the dominant factor. I was implying the 20w-40 pumping/flow performance at 0 F would have been like the specified 5w-30 at -33 F in the given thought experiment.
I'll throw a wrench in the understanding of many, including myself. It appears that the 0w-40 is actually thicker at cold temperatures (circa 0 deg F) than a 5w-30. Am I misunderstanding or is this a lapse in layman oil grade casual knowledge? (The 100 C rating impacts the slope of the curve through the second data point.) In which case, 0w means something, but not when taken out of context.
Plotted: 0w-40 (orange) vs 5w-20 (pink) vs 10w-30 (green) down to 0 deg C (-18 F). The nominal 10w-30 is actually thinner than the 0w-40 within the range of "cold" starting that matters to most of us.
Are these curves erroneous? Can the V vs T curve be completely understood with two points, 40 C and 100C, or is there more to the story at the extremes?
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I say don't try crank anything that has oil thicker than about 16,000 cP.
A 20w at about 4f (all the charts I found are in c) is around 6,000cP so it shouldn't be a problem.
Not recommend.
For me, if the 5w weight oil in my vehicles hits 16,000 cP I figure don't have to worry about it, cause at that point I'm probably dead.
Am I correct in saying a 20w-40 at 0 C is actually thicker than a SAE 20w (not to be confused with SAE 20) at same temperature?
It takes actual testing on a cold cranking simulator to give an idea of what the oil is going to do whenever it really starts to thicken up at those brutality cold winter temps.
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I realize that now. Clearly these are pretty stout, we'll designed motors if they put up with this abuse.
I figured the straight 20 weight winter version was just on the thinner side of "20 weight". I'm not sure I never did a deep dive into the straight grade winter weights vs anything else. I don't think I've ever seen a chart where the straight grade winter weights were plotted out. Just seen them on the abacus style temperature recommendation charts.
Maybe someone has.
Like I said before, it depends on exploitation, engine etc.
Do it for science but remember that I'm almost exclusively talking about M1 0w40 and a short interval of say under 5k miles. The only other 0w40's which I've seen shear on UOA's is Redline and one or two samples with Ravenol. The UOA database should be full of examples.
Yes but as I noted, cranking would not be my first concern. It would be pumpability, and that isn't determined by the vehicle. Cranking can be mitigated a bit with a good battery and starter, but if the oil won't be pumped that's going to cause failure in a hurry.
OVERKILL
$100 Site Donor 2021
Yeah, just because it will start doesn't mean it's getting oil. How long it takes to get the oil hot enough to actually go up the pickup I'm sure would do exciting things with wear.
I first check the owner's manual (OM) engine oil requirements to make sure I meet and/or exceed ...
I do NOT chase 0W unless required by the starting temperatures (SAE J300).
I may chase some approvals (exceeding the OM) which require a 0W but that's a different story. I go top down.
I recently bought a few Castrol Edge Euro 5W-30 for $23.xx / 5 qt. It's a good oil, technically API SL that "exceeds" SL. Has a bunch of Euro approvals.
Castrol Edge Euro 0W-30 is the only 0W that I may chase and a very good oil but $40 / 5 qt. Not worth the price for me since non of my cars require a Euro approval.
Have some M1 FS Euro 0/5W-40 I got on sale for $23.xx but just for the price since I'm not fond of wide spread oils in general but bunch of Euro approvals at a good price overruled my concerns.
I run mostly M1 EP 10W-30 and Valvoline EP 5W-30 in one of my cars I care the most about ... That should tell how much I care about 0W and/or Euro approvals in general. lol
But in general, I pick approval(s) first, then go from there. I don't chase 0W just because.
Top-down vs. bottom-up!
I do NOT chase 0W unless required by the starting temperatures (SAE J300).
I may chase some approvals (exceeding the OM) which require a 0W but that's a different story. I go top down.
I recently bought a few Castrol Edge Euro 5W-30 for $23.xx / 5 qt. It's a good oil, technically API SL that "exceeds" SL. Has a bunch of Euro approvals.
Castrol Edge Euro 0W-30 is the only 0W that I may chase and a very good oil but $40 / 5 qt. Not worth the price for me since non of my cars require a Euro approval.
Have some M1 FS Euro 0/5W-40 I got on sale for $23.xx but just for the price since I'm not fond of wide spread oils in general but bunch of Euro approvals at a good price overruled my concerns.
I run mostly M1 EP 10W-30 and Valvoline EP 5W-30 in one of my cars I care the most about ... That should tell how much I care about 0W and/or Euro approvals in general. lol
But in general, I pick approval(s) first, then go from there. I don't chase 0W just because.
Top-down vs. bottom-up!
Which approvals require a 0W winter rating?
You are being a nitpick again!
You know what I mean, and I know that you know, but you can't help it.
I am sure you can read a whole book and find a sentence or two to dissect and find flaws ... Political campaigns are hiring big time right now! I would utilize that talent. lol
By "requiring a 0W", I meant requiring a base oil that would ultimately meet the SAE 0W as such can no longer be labeled a 5 or 10W, etc.
I won't be surprised if you dissect this also. Like I said, you can't help it.
OVERKILL
$100 Site Donor 2021
PSA B71 apparently, 0W-20 only
Of course none explicitly, but I’m pretty confident you’ll never see any of the newer BMW, Mercedes, and VW approvals with 5W rating.
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