Pretty much.

If i was going to switch from mobil 1 again, i'd go back to motul again lol

Motul is actually a good oil. Proven.

Amsoil isn't really proven. It's only proven by the paid soldiers all over the interwebbzzzzzz lol

 

Yep sure do. They had to add "dino oil," which is what most all oils sold in the US are made from as it swells seals!

Rather than my usual link to the article that describes the situation best, I posted it below. To summarize the "true synthetic oils," Group IV are polyalphaolefin (PAO) base that started with Ethenlen gas (NO NOT Nartural Gas like some today.) As the article states "it cost twice as much to produce." BUT it did not change viscosity nearly as much with temperature so a light weight oil could behave like a higher "weight" oil at high temperatures. It also could operate at a higher temperature. Actually great stuff (for the day.)

My modified Corvair when pushed had oil temps of ~325 F and it was breaking down. It formed scum in the intake tube and I I was changing heavy weight multiviscosity oil often! With the original Mobil 1 - no breakdown! That all changed ~2000 when Mobil lost a suit to Castrol and all the producers of Group IV type oils for automobile use switched to "more highly refined "dino oil" because it was half the cost! The retail price did in fact cut in half!

You can still buy Group IV oil in Europe BUT have not seen any US oil listed as Group IV! Have seen "it performs like Group IV" in Amsol literature but so can a number of good oils! As the article states, "Petroleum refiners in recent years have learned how to break apart certain undesirable molecules -- wax, for example, which causes thickening at low temperatures -- and transform them by chemical reaction into helpful molecules." That was when it was written, ~20 years ago. A Forum member Petroleum Engineer notes more improvements have been made in refining "dino oil" (that comes out of the ground from old Dinosaurs and plants of that era!) Perhaps in many regards todays oils are better than Group IV "Old Mobil 1."

And I don't buy that some oils don't meet the GM spec because they don't want to spend the money! In fact the article says something I don't accept, "The Society of Automotive Engineers (SAE) and the American Petroleum Institute (API) supported NOT defining synthetic as Mobil did because they were NOT unbiased! Both had performance specs they wanted used BECAUSE they were getting like a ~penny a quart IF you quoted your oil met their spec! They were not banking on GM developing their own standard! SAE and API still get a small amount per quart but GM lowered their cost, especially for small producers so it's BS saying the folks don't want to pay!

SIDEBAR By Patrick Bedard, Car and Driver
"Now that the meaning of "is" has gotten so slippery you need to grab it with both hands, we'd better keep an eye on longer words, too. (My note, Bedard was referring to the Clinton Lewinski affair and Bill's famous statement, "It depends upon what the meaning of the word 'is' is.)
One's already gone squirmy on us -- "synthetic," as in synthetic motor oil.
Most guys know two things about synthetic oils. First, the price is three to four times that of conventional oils. Second, they're not real oil, not made from crude.
News flash: Scratch that second part. Now motor oils derived from crude may be labeled "synthetic." But they still cost over four bucks a quart.
Bait and switch? That's the obvious conclusion. Except in this case the advertising ethics people have given their approval.
Here's what happened, according to a detailed account published in the trade magazine Lubricants World. Late in 1997, Castrol changed the formula of its Syntec "full synthetic motor oil," eliminating the polyalphaolefin (PAO) base stock (that's the "synthetic" part, which makes up about 70 percent by volume of what's in the bottle) and replacing it with a "hydroisomerized" petroleum base stock.
Mobil Oil Corporation, maker of Mobil 1, "World's Leading Synthetic Motor Oil," said no fair and took its complaint to the National Advertising Division (NAD) of the Council of Better Business Bureaus. NAD often arbitrates between feuding advertisers on their conflicting claims.
The notion behind synthetic motor oils as we've known them is an elegant one. Instead of relying on the cocktail of hydrocarbons contained in crude oil, why not go into the laboratory and build the perfect base stock from scratch, molecule by molecule? The synthesizing of PAO starts with ethylene gas, a simple two-carbon molecule, and builds till it gets 10-carbon molecules, then combines three of those to form PAO. The result is a fluid more stable than the usual base oils derived from crude. It keeps flowing at low temperatures. It's more resistant to boiling off, and more resistant to oxidation, which causes thickening with prolonged exposure to high temperatures.
Still, there's more than one road to the point B of improved stability. Petroleum refiners in recent years have learned how to break apart certain undesirable molecules -- wax, for example, which causes thickening at low temperatures -- and transform them by chemical reaction into helpful molecules. These new hydroisomerized base oils, in the view of some industry participants, "provided properties similar to PAOs but cost only half as much," Lubricants World reported.
The argument before NAD tiptoed around the obvious -- does the consumer get four bucks' worth of value from each quart of synthetic oil? -- and plunged straight into deep semantics. Mobil's experts said "synthetic" traditionally meant big molecules built up from small ones. Castrol's side held out for a looser description, defining "synthetic" as "the product of an intended chemical reaction."
What do unbiased sources say? It turns out that the Society of Automotive Engineers (SAE) and the American Petroleum Institute (API) both have technical standards covering motor oils, and both of these organizations in the '90s backed away from their old definitions of "synthetic," leaving lots of room for new interpretations.
In the end, NAD decided that the evidence "constitutes a reasonable basis for the claim that Castrol Syntec, as currently formulated, is a synthetic motor oil," said Lubricants World.
The obvious question now: Has the term "synthetic motor oil" been opened up to the point that it no longer means anything? Maybe. But here's a better question: Did synthetic ever mean what we thought it meant?
"Great oil" is what most guys think it means. "At that price, it's gotta be great stuff!"
Okay, but how great? Your car's manual tells what motor oil you should use, and with few exceptions, that description will consist of only two specifications. One is for viscosity, such as 10W-30; and another is for the API service grade, SJ being the current one for gasoline passenger cars."

 

People usually correlate price with quality with oil. Which isn't the case.

For example. Supertech, which costs pennies, is a GREAT oil. Something like royal purple, amsoil, for the price, is not.

If anything, the best bang for buck synthetic is QSUD. Which is dexos approved too.

But i still with mobil 1 because it keeps whatever warranty i have left happy. And it's readily available. And it's always on sale at walmart lol

 

Mobil 1 ESP, dexos2 0W-40 is NOT yet available at Walmart at the same low price as most others including European 0W-40 that also does not meet a dexos spec!.

 

You folks staying with Mobil 1 because it keeps the warranty intact understand that ANY Dexos 2 approved oil in the right weight keeps the warranty intact right?

 

^^^
The last I looked there is no other 0W-40 dexos 2 oil other than Mobil 1 ESP.

 

I still use 5w30. That's what my owners manual states, that's what has always went in.

 

Of course. But if looking at all dexos approved oil, your natural instinct will lean towards mobil 1 time and time again. Because again, readily available, proven, and because that's what GM puts as a factory fill.

0w40 no but motul x-clean EFE was dexos 2 that i ran for 2 oil runs. But the price fluctuations made me go back to Mobil 1. Got a 5L jug for 32 bucks. Next time around it was 55 lol.

 

Castrol Edge has a 0W-40, https://www.gmdexos.com/brands/dexos2/index.html

 

Maybe your natural instinct will, mine will tend toward the Castrol Edge.

 

Too bad it isn't available here in the states. It's not even shown on the Castrol web site.

 

Well that sucks. I guess folks will have to stay with Mobil 1 for a while longer.

 

I'm not worried. I don't like castrol anyway.

I only use their magnatec in my truck because the oil was given to me lol.

 

These guys throw Magnuson Moss around pretty loosely. If you read it carefully, a warranty cannot be denied as long as the “part” meets the manufacturers specification. In this case, the latest soecification is Dexos I Gen 3. This is a full synthetic That supersedes the old GM4718M.

 

 

I see this is an old thread, that got revived. But since it came up:

The 2023 Owners Manual requires 0W-40 motor oil rated dexosR. I contacted Amsoil in Oct 2022 and asked if they have a product they recommend for use where dexosR is specified. At that time, they did not.

If you use the search by car feature on their site, you will see that for 2023 Corvette there is no recommended product. They do recommend one for 2022 Corvette - the 2020-2022 Owners Manuals require 0W-40 dexos2.

Some may recall that the "Mobil 1 0W-40 ESP Forumla" (not to be confused with other Mobil 1 products that also have ESP in the name) which was rated dexos2 became "Mobile 1 Supercar 0W-40" which is rated dexosR. But, that does not mean that all dexos2 0W-40 motor oils will meet the dexosR specification.

I have nothing against Amsoil products, and I use them in my older collector cars. But in my 2021 Corvette I will be using motor oil that is certified dexos2 or dexosR. At the present time, Mobil 1 Supercar 0W-40 is the only one certified under dexosR. There are several certified for dexos2. They are listed at the gmdexos website that is referenced in the Owner's Manual.

 

Just what is the deal with AMSOIL I see it advertised on some gear head shows but have NEVER been told to use it by anyone or any mechanic why is that?

 

Mobil has stated, in writing, that Mobil 1 Supercar Dexos R is just a rebranding of ESP Dexos 2. There is zero difference in the oil or the spec. So if an oil meets Dexos 2, it meets Dexos R. Amsoil's website say their oils "already outperforms Dexos R." Which is nice, and maybe even true, but without the Dexos R (or Dexos 2) certification GM isn't going to care about Amsoils marketing claims.

Is using Amsoil in your Corvette likely to cause any problems? No. But neither is it likely to perform any better than Mobil 1 with the proper spec.

Amsoil is like a cult. There is a core group of users buyers who believe, based on Amsoil's marketing claims, that it is far superior to anything else. I haven't checked in the long time, but in the past there was ample testing by independent testers that demonstrated that while Amsoil proved better in some tests, it fared far worse in others. I expect to get attacked by the true believers for pointing this out.

 

Remember not to confuse oils with oil specs though. The dexos 2 esp 0w40 is indeed the same as the m1 supercar 0w40 that is dexos r but that doesn't mean the specs themselves are the same....just that m1 0w40 esp meets both specs. I'll be meeting with m1 reps tomorrow and wonder if they will be willing to explain what is different if anything in the tests and limits between dexos 2 and dexos r

 

1. "]Mobil has stated, in writing, that Mobil 1 Supercar Dexos R is just a rebranding of ESP Dexos 2": Not quite. They said that "Mobil 1 ESP Forumla 0W-40" was rebranded as "Mobil 1 Supercar 0W-40". "Mobil 1 ESP 0W-40" and "Mobil 1 ESP Forumla" are two different oils with separate dexos2 approvals. This can be seen on the gmdexos site I mentioned above. It is also not the same oil as "Mobil 1 ESP x3", which is also a different dexo2 certified oil. The only oil that was rebranded "Mobil 1 Supercar 0W-40" was 'Mobil 1 ESP Forumla 0W-40".

2. " There is zero difference in the oil or the spec.": Not quite. There is no difference between "Mobil 1 ESP Forumla 0W-40" and "Mobil 1 Supercar 0W-40". But it does not follow that there is no difference in the dexos2 and dexosR specifications. dexosR and dexos2 could be, and likely are different specifications. "Mobil 1 Supercar 0W-40" and "Mobil 1 ESP Formula 0W40" meet both specifications. But other dexo2 approved oils may not meet the dexosR specification. No other oils are shown as meeting the dexosR spec on the gmdexos site yet.

3. As for AMSOIL claiming they exceed dexosR - I could not find that and I posted an email above where they said they did not meet dexosR- from October of 2022. When I entered the 2023 Corvette, which requires dexosR on their website today, it provided no recommended product. But for 2022 (which was a dexos2 requirement) it recommends an oil. If you have the link to where they now claim to exceed dexosR please share - I can't find it. Edit update: In post 81,Red Mist Rulz provided this link
https://blog.amsoil.com/gm-dexos-mot...pecifications/
to a recent (March 9, 2023) Amsoil news item that does say it has product that "outperforms dexosR. The look-up guide on that site still does not recommend an oil for 2023 Corvette.

Attached is the add showing that "Mobil 1 ESP Formula 0W-40" is now "Mobil 1 Supercar 0W-40". Note the word "Formula" in the name. It is part of the name, and it is not the same as the other Mobil 1 oils that also have ESP in the name. That ad does not say that dexos2 and dexosR specifications are the same, only that the two named oils are the same.

Attached are clips from gmdexos site. This show that there are different Mobil 1 oils with ESP in their name. The only one of these that became "Mobil 1 Supercar 0W-40" was the "Mobil 1 ESP Formula 0W-40".