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Euro oil spec thats better than dexos 1/r?
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OVERKILL
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Wasn't a tactic, just being pedantic
edyvw
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There is nothing to try. Catch up with readings and come back to discuss.It's not complicated in terms of explanation. All those tests done are targeted. It's very specific. How the tests are performed, and how the results are interpreted within the context of an engine's design envelope, is where it gets complicated.
Because that part is so complicated is the reason I say stay within the manufacturer's recommendations. They've done all the work for you. Take advantage of it. The creative energy and research can go into selecting within the specs.
I'll try to frame it from the perspective of many here - Porsche and Euro oils. 2.0T Macan specs C20. Why not A40 if it protects better? Do you know because I don't. I do know that they know
You came to talk constitutional law, and didn’t go through American History 101.
OVERKILL
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So, your position is that an A40 oil will not perform better than a basic API SN oil in an application that just calls for API SN?
So then how do you explain layered approvals? For example ACEA A3/B4 is foundational for the full-SAPS Euro approvals. But each approval is different, and each application is different. The same goes for C3. If we use an oil being discussed in this thread, M1 ESP X3 0W-40, based on C3, had Porsche's approval, Mercedes' approval, BMW's approval, FIAT's approval, GM's approval, along with your API SN Plus approval. Is it your belief that if used in a Honda, that this oil isn't going to perform better than your bog standard API SN oil that the Honda calls for?
The entire reason GM came up with dexos was because your bog standard API/ILSAC oils were not good enough. They wanted something better; they wanted a better oil. The European marques had already been doing this for decades, and GM had come up with some specific performance standards, like the Corvette standard, but never something universal like the Euros. For dexos1, the foundation was your basic API/ILSAC standard, but with stricter limits for some test parameters as well as some GM-specific tests, such as TJ5JP-L4, TU3M Wear Test, MB M111 Black Sludge, M271 sludge, M111 Fuel Economy, GM oxidation and deposit test, GM Aeration test, GM Pre-ignition test (LSPI), GM Turbocharger deposit test. Most of these also apply to dexos2, but along with those we also have DV4TD, OM646 LA wear test, OM602A wear, VW DI and Aeroation Test GMPTE-T.
Now, a sharp eye might notice the MB and VW stuff there. That's because dexos1 and dexos2 (and subsequently dexosR I assume), incorporate a few of the Euro engine tests. M271 sludge for example, is part of all of the MB approvals except for 226.5 and 226.51. The M111 Fuel Economy test is part of every MB approval. The OM 646 LA Wear Test is also part of every MB approval...etc
So, I think your premise is flawed here. GM saw fit to include Mercedes and VW engine tests as part of dexos. This reinforces @chris719's point about "engines being engines" and disparate tests having considerable merit. As I said earlier, approvals in concert raise the overall bar for the performance of the product, and this appears to reinforce that.
interesting never thought about it. Can the FCP Euro Lifetime Replacement policy be used against non-Euro cars, or it should be only Euro car? I have 2 V6 old school Japanese cars which could use A3/B4 Full Saps Oil
Go for it
Dexos Schmexos. 
I know it’s probably because it was the first word in your post, but not even GM believes dexos deserves to be capitalized. That right there is a sign they don’t think it’s anything special…Dexos Schmexos.
4WD
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And there is a dexos D now for light diesel - like ESP X2 …
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No, engines aren't engines. Oil isn't oil.
You are right, the lighter oils like 0w-20, specifically resource conserving, do improve fuel economy. Anything else maybe? What other functions of oil are there?
Porsche sourced the 2.0T engine in the Macan from VW - EA888. Like many TDI engines, it has oil squirters to cool the pistons. See below (Audi uses it, too).
If a heavier oil, such as an A40 spec 0w-40 or 5w-40, is used that could be problematic. The oil pump has a pressure regulator. If pressure rises too high then the bypass spring opens to hold set pressure. There will be a higher volume of oil pumped to the system for the lower viscosity oil for the same pressure. Therefore, in this instance, C20 protects this engine better than A40 by providing the specified volume of oil for adequate cooling..
A40 might be a stricter spec theoretically, but practically the level of actual protection varies with application.
Does that not make sense? Design considerations. Oil and the engine tested as a unit. Sure, there may be engines that use piston squirters and call for A40. This oil spec for this oil system. Porsche tests extensively, remember?
So, C20 or A40 in this engine?
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Not really, not at least within the window we are talking about. A 0W-20 at room temp 25C is around 4-5x thicker than the 0W-40 at operating temp. The engine must be designed to operate from sub-zero temps to death valley and under heavy load. If the increased viscosity difference from a 20 to a 40 was going to be problematic these engines would be destroying themselves in cold climates every day. The bypass would be open all the time in cold climates and short trips. I have run 0W-40 in a Mazda 3 2.5 specifying a 20 for 10s of thousands of miles with good UOA results and I'm at around 150k miles.
Do you think that's the only engine with piston squirters? My BMW S54 runs 10W-60 and people have run as thin as 0W-40 in them and there is no problem with piston squirters or even the extremely overcomplicated high pressure VVT. There is no way that C20 protects better. Period. C20 is for grocery getters sold in volume to bring up CAFE so the "real" Porsches can use their 3.8 HTHS oil.
The fact that GM just took an engine using 0W-20 and switched everyone to 0W-40 plus already uses the thicker oil in a very similar design shows you there is no magic with low viscosity. Nevermind the Toyota manuals from Australia that allow 10W-40 for engines that ship with 0W-16 in the US, or the Gen 1 Ford Coyote track recommendation of switching from 5W-20 to 5W-50, BMW allowing for 3.5 cP HTHS in engines shipping with 2.6 cP 0W-20, etc.
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Operating temp, obviously. Have you ever looked at a vehicle's tune? There are ECT modifiers for fuel and spark to protect the engine by ensuring combustion stability at cold temps. Never mind that colder oil cools better offsetting the lower flow at low temp. Why are you bringing up cold start?
You might as well say piston squirters aren't necessary. Their entire one and only function is to supply a volume of cooling oil to the pistons.
Maybe you should take a basic physics course. A basic 0W-20 is around 8.8 cSt KV100. Mobil 1 FS 0W-40 is 13.8 KV100. This difference is nothing compared to what the engine sees during the course of warm-up even if you start the car in Phoenix in the summer. The 0W-20 is 3x thicker than that 13.8 cSt at 40 C / 104 F.
There is no issue with the piston squirters, come on. If you did have a cooling problem it would exhibit itself as higher oil temps which would one, be observable, and two, continue to thin the oil out at a rate that is roughly exponential. At higher and higher temps, depending on a lot of factors including VI, you can see that the viscosities start to converge.
BTW, the GM L87 / LT engines have piston squirters and GM goes THICKER for heavier duty / higher temp applications.
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That is all correct. What's that have to do with piston squirters cooling the piston? They are needed when the engine is under load and at temp. The Xw-20 flows more than the Xw-40 substantially.
I don't know how you got cold oil pressure and bypassing oil pump starving the bearings out of what I said. I really don't.
Like a higher viscosity oil will register more pressure because it has more resistance to flow. This means that for pressure to be maintained, flow has to be reduced. This is done by the bypass spring. Reduced flow, alright? Less cooling oil volume.
Refresh and read my update, sorry posted too soon. I'm done wasting my time anyway. Never said a word about bearings either. The idea of little EA888 needing CAFE oil to cool its pistons is pretty funny.
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Again, your talking about a different engine with a different spec. GM most definitely monitored the performance of the oiling system in that engine when they approved the oil. The L87 isn't an EA888. This despite me already pointing out that just because an engine has a piston squirter...go ahead and be done that's fine.
Last post, for sure. What does oil do as it gets hotter, like when you are transferring more heat into it because you can't cool your commuter 2.0L engine's pistons
? Surely, if your argument made any sense, manufacturers would be recommending thinner oils on track not thicker oils on track.- Joined
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Well, I'm glad you're finally realizing that one of the functions of oil is that it cools components.Last post, for sure. What does oil do as it gets hotter, like when you are transferring more heat into it because you can't cool your commuter 2.0L engine's pistons
What it does is it thins out. Are you saying the engine needs to run excessively hot for the -40 to flow like the -20 at the correct temp? That's true, very good.
A commuter 2.0L. You have no idea what kind of stresses are in that engine. Specific HP for starters, but the overall architecture. Did you happen to do all the FEA's and CFD's when you built the EA888?
edyvw
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I have told you before to read things here before you come to discuss, because it is apparent that you discuss things as you find them on the internet at that moment.
EA888 is not sourced from VW. VW owns Porsche and Audi, and during the development of those and numerous other engines that are shared, all those companies have an input, etc., as to how to develop the engine. So, EA888 is a Porsche engine as it is a VW engine.
Now, onto this nonsense about 0W20. Engines can use any oil viscosity as long as it is higher than the lowest one recommended. In EA888 you can use Motul 300V 20W60 Le Mans for all intended purposes. If I could have a nickel for all the EA888 I have seen on track using Motul 300V 10W40, Mobil1 5W50 etc. I could buy a fancy dinner for all my family.
Also, kind of important, VW508.00/509.00 and C20 approvals are only current for the last 2-3 years. Before that, those SAME engines that have those same pressure regulators used VW504.00/507.00, which are HTHS 3.5cP or higher, almost W40 oils. And before that, which was 2019, they used VW502.00 mostly in 5W40 flavor! Take into consideration that on many markets VW still uses VW502.00 oils which are HTHS 3.5cP minimum, and come in XW30 and XW40 flavor because of their gasoline quality, or lack of.
And here is my point, we discussed this, EXACTLY this, numerous times, not only in this section, but in other sections too. And yet, here we are.
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