I was exaggerating. However, I will say these two things:I am saying this with the utmost respect for you, your work, and your contributions to this forum: have a little faith that the engineers and formulators at ExxonMobil and Infineum know what they are doing.
I think Mobil said they tested this oil for over 2 years.
Pretty sure it will work just fine and the engine will out live the rest of the car 5 to 1.š
Sold!In that case, why go for Supercar oil, when you can have Bad A$$ racing oil!?!
View attachment 108906
I think that is likely the case.I was exaggerating. However, I will say these two things:
Interestingly, GM used to recommend an ILSAC 5W-30 for Corvettes as far as I know, but it appears that they wanted to jump on the 0W bandwagon, also increasing the KV100, which resulted in a two-step increment of the XāY spread in XW-Yāor a drastic increase in the VII content.
- The VII contents have been increasing more and more and the base oils have been getting thinner and thinner to make the oils more fuel-efficient.
- A 0W-40 oil is an oxymoron in general. It pretends to be thick but it isn't due to the thin base oil and the high VII content. A good ILSAC 5W-30 will run as thick as a 0W-40 and possibly even thicker with only a third of the VII content. This is because of the temporary shear at very high shear rates (well over 10ā¶ sā»Ā¹) and also the permanent shear of the VII. Therefore, unless the OEM recommends a 0W-40, you're better off with a stout ILSAC 5W-30.
Also, worth thinking about, but you aren't limited to the API xW-30 and below phosphorous limit with an xW-40.I think that is likely the case.
I would say I think GM wanted an oil slightly thicker than regular M1 5w30, which like 99% of most 5w30's on the market, are designed with fuel economy in mind and would drop to a high 20 grade in some instances. With the 0w40, you're getting a global/all climate oil that will at most drop to a high 30 grade. It also handles aeration better. So I do see some advantages in favor of the 0w40. It's not hard to make a more shear stable 0w40. It's intentionally designed as is for a reason.
Over the years I've read different things from GM engineers on Mobil 1 and they always said if there was something better, they'd be using it. Take it with a grain of salt...but they've done all the testing so....
One thing to consider as well is that it's the entire formulation that makes an oil work. The 0w40 is using a different base oil blend than the standard M1 line, at least from what we can assume based on various sources.
I've seen numerous 0w40 UOAs and they all perform very similarly, including the boutique brands.
Look at Amsoil 0w40 Powersports Oil or Red Line 0w40. Both significantly thicker.
View attachment 121066
Well, the SRT 0W-40 wouldn't pass the volatility requirements for MB 229.5 for example (10% limit, the oil is 13%). API limit is 15% and dexos1 limit is 13%, not sure about dexos2 or dexosR.How could an oil good for a supercharged Hellcat be unsatisfactory for a direct injected, naturally aspirated Vette?
Does dexosR have a soot-handling test?Well, the SRT 0W-40 wouldn't pass the volatility requirements for MB 229.5 for example (10% limit, the oil is 13%). API limit is 15% and dexos1 limit is 13%, not sure about dexos2 or dexosR.
GM's dexos approval does add a decent number of new tests the oil has to pass that aren't included in the basic API stuff. Their royalty arrangement is a bit gross, but it is what it is, though, IIRC, its terms changed recently.
Note that the Hellcat and SRT engines are all port injected, so DI soot handling isn't really much of a concern.
Lubrizol doesn't have dexosR on their spider chart yet, but dexos2 did.Does dexosR have a soot-handling test?
I would think all API SP/ILSAC GF-6 oils would have excellent DI soot handling because of the new timing-chain wear test. Therefore, this is a nonissue.Lubrizol doesn't have dexosR on their spider chart yet, but dexos2 did.
High SAPS is not something you necessarily want in today's modern engines. It reduces oxygen sensor, spark plug, and catalytic converter life and increases the intake-valve deposits. Moreover, the newer AW/EP/FM additives used today, such as the organic FMs, more than make up for the reduced phosphorus.Also, worth thinking about, but you aren't limited to the API xW-30 and below phosphorous limit with an xW-40.
If you want a "stout" 5W-30 with little VII content and a thick base oil, the answer is probably Pennzoil Platinum 5W-30 SP/GF-6. (It used to be Valvoline Advanced Synthetic in GF-5 days, but Valvoline thinned down the GF-6 formula.) It is thicker than all of M1 FS/ESP/ESP X3/ESP Formula 0W-40 for high-revving applications (with shear rates well above 10ā¶ sā»Ā¹); so, you will get less engine wear with it than with these 0W-40 oils. I would also stay away from the Pennzoil Ultra varieties if you want a stout oil, as they use thinner base oils even though they might have a slightly boosted additive package.I own a 2022 Corvette, and before that, a 2015 with a dry sump engine. The 2015 came with a 5w-30 recommendation, which GM later changed to 0w-40. After the warranty period on the 2022, I think I will run 5w-30. The car is out of service all winter, so sub freezing operation never occurs. And the car is almost always under 3000 rpm.
And I am suspicious and resentful of the Dexos licensing requirement. I actually prefer Pennzoil Ultra Platinum. Shell lubrication experts are just as good as the folks at ExxonMobil. How could an oil good for a supercharged Hellcat be unsatisfactory for a direct injected, naturally aspirated Vette?
Tying a warranty to the use of products that GM collects licensing fees probably violates Moss-Magnuson.
You can use Pennzoil Platinum Euro L 5w30. It's Dexos 2. That's what I'm using in my Corvette. I'm never going to track it.I own a 2022 Corvette, and before that, a 2015 with a dry sump engine. The 2015 came with a 5w-30 recommendation, which GM later changed to 0w-40. After the warranty period on the 2022, I think I will run 5w-30. The car is out of service all winter, so sub freezing operation never occurs. And the car is almost always under 3000 rpm.
And I am suspicious and resentful of the Dexos licensing requirement. I actually prefer Pennzoil Ultra Platinum. Shell lubrication experts are just as good as the folks at ExxonMobil. How could an oil good for a supercharged Hellcat be unsatisfactory for a direct injected, naturally aspirated Vette?
Tying a warranty to the use of products that GM collects licensing fees probably violates Moss-Magnuson.
Higher phosphorous doesn't mean high SAPS. Most of the low SAPS Mobil ESP xW-40's have phosphorous at 900ppm, which is significantly higher than the 600-800ppm the API mandates for xW-30 and below.High SAPS is not something you necessarily want in today's modern engines. It reduces oxygen sensor, spark plug, and catalytic converter life and increases the intake-valve deposits. Moreover, the newer AW/EP/FM additives used today, such as the organic FMs, more than make up for the reduced phosphorus.
RDY4WAR said:ZDDP is only active in boundary lubrication and is more effective on ferrous metals where the sulfur part of ZDDP reacts with iron surfaces to form a barrier of iron sulfide. The rod and main bearings operate in hydrodynamic lubrication and ideally should never encounter boundary lubrication. The rings go through all 3 lubrication regimes and rely on ZDDP at and near TDC and BDC up to ~20* each way.
There's no anti-wear additive that can replace ZDDP in effectiveness. However, there are other additives that synergize well with ZDDP, boosting anti-wear properties.
As with most anything, more ZDDP is not always better. ZDDP is created through reacting phosphorus pentasulfide with various alcohols to make dialkyl-dithio-phosphoric acid which is then neutralized (to a degree) with zinc oxide to form zinc-dialkyl-dithio-phosphate (ZDDP). This means ZDDP is an acidic ester. (neutral and basic ZDDPs exist but aren't used in engine oils) In some cases, too much ZDDP can cause corrosive wear. As far as interaction with detergents, ZDDP is acidic and detergents are acid neutralizers. You can see how that interaction can be conflicting. The synergy of ZDDP with other anti-wear / friction modifier / extreme pressure additives is also important and has to be accounted for when blending as more of one could throw off synergy with another and actually hurt more than help. This is why proper synergy of additives is important and why playing backyard shadetree chemist with a supplement is never a good idea.
The difference between API/ILSAC and ACEA limits is that the former requires 600ā800 ppm phosphorus, whereas the latter requires 700ā900 ppm phosphorus. Note that there is no lower or upper limit in the A/B categories, and there is no lower limit in the C4 category. That's the real reason why you see more phosphorus in M1 ESP etc.ānot because they would show more wear in the wear tests if they reduced the ZDPP a little but because more like a result of ACEA red tape. It's akin to Ford requiring a minimum of 1,000 ppm phosphorus for their diesel engines.Higher phosphorous doesn't mean high SAPS. Most of the low SAPS Mobil ESP xW-40's have phosphorous at 900ppm, which is significantly higher than the 600-800ppm the API mandates for xW-30 and below.
Phosphorous is only an issue if a lot of it ends up in the exhaust of course, and, if you have that going on, you probably have bigger issues.
Per @RDY4WAR:
This is why we see ~1,000-1,100ppm in the Euro full-SAPS oils, despite there being no limit, so it could be much higher. And of course this is why we continue to see ~900ppm of phosphorous in the ESP oils. I firmly believe that the API limits, imposed on the lighter grades of oil (xW-40 and above are exempt) are done with the intention of allowing for higher levels of consumption with cheaper oils within the warranty period and the catalysts still surviving. The Euro marques don't have this limitation, I assume due to stricter limits on things like Noack. Even M1 ESP X2 0W-20 has 880ppm of phosphorous, above the API limits, but it has C20, JLR.51.5122, dexosD, ACEA C5/C6, MB 229.71 and VW 508 00/509 00.
I'm aware of the limits. That doesn't track though. Most of the API oils we see are in the 700-800 range. Mobil runs 760 on pretty much everything non-high mileage, 800 on the high mileage, right at the limit. This is well within the 700ppm lower limit you've indicated for ACEA, but their ACEA ESP oils that are xW-40's are all right at the upper bounds at 900ppm and right at the API upper limit of 800ppm for the xW-30's, clearly there is a reason for this.The difference between API/ILSAC and ACEA limits is that the former requires 600ā800 ppm phosphorus, whereas the latter requires 700ā900 ppm phosphorus. Note that there is no lower or upper limit in the A/B categories, and there is no lower limit in the C4 category. That's the real reason why you see more phosphorus in M1 ESP etc.ānot because they would show more wear in the wear tests if they reduced the ZDPP a little but because more like a result of ACEA red tape.
But most diesel oils are well above that anyways. TDT has 1,100ppm of phosphorous for example.
The limit for phosphorous under SJ was 1,000ppm for xW-20 and xW-30.ZDDP levels used to be much higher.
Redline might argue with you on thatDid the API SL and lower oils caused less wear? Absolutely not. In fact, they API SL and lower showed more wear because they lacked the modern AW/EP/FM additives, including the organic FM additives, that are now used in combination with ZDDP.
Mobil doesn't use 650ppm in their ILSAC 0W-20 though, they use 760, and 800ppm in the High Mileage version:Can ZDPP be entirely eliminated? Probably not. How much ZDDP is enough? I think the 650 ppm phosphorus Mobil uses in their ILSAC 0W-20 oils might be enough. Of course, there is also the question of what type of ZDPP, which makes a huge difference, more than the amount of ZDDP used, that was discussed by me and @RDY4WAR.
This is a recent change. The 10/2019 copy of that document showed 650ppm of P for the EP and AFE 0W-20's.Mobil doesn't use 650ppm in their ILSAC 0W-20 though, they use 760, and 800ppm in the High Mileage version:
View attachment 121134