StormRune

The normal Mobil One carries the Porsche A40 approval too, but it is not named the "European Car Formula"... which is also A40 approved. You can see them as two distinct products on the Napa site at the links below. The Mobil engineer told me they are different products, both the base and the additive blends and this was backed up by some material I had previously found elsewhere. I'll hunt it down and post it when I find it.

https://www.napaonline.com/en/p/MOR112986

https://www.napaonline.com/en/p/MOR120760

StormRune

I still haven't found the write-up yet, but you can see from the product detail sheets there are differences, both in approvals and in numerous categories including viscosity (70 on the normal full synthetic, 75 on the European... both 0W-40). Here are links to the product sheets for each:
https://www.mobil.com/English-US/Pas...bil-1-FS-0W-40
http://www.mobil.com/english-AU/Pass...XXMobil-1-0W40

Notice that only the European Car Formula hits the approval for the Nissan GT-R, while the Porsche A40 is on both.

StormRune

Okay, from my reading it appears that what Mobil sells now as the base Mobil 1 0w40 is still a full synthetic but over a year ago was reformulated to use something called GTL (Gas to Liquid) technology in forming its base stock. To get the old formulation you have to buy the one with the "European Car Formula". Google "Mobile 1 0w40 GTL" for more info.

So GTSMeister: Note that the US Mobil site does not list the European Car Formula version so that is why you are seeing only one. But it does appear you are correct that for a long time Mobil One 0w40 had only one formulation, but now they seem to be producing a cheaper-to-manufacture GTL version for North America under the old name and it doesn't seem to perform quite as well... so if you buy that you are actually getting a different oil than you used to. I know that Walmart does not carry the better formulation as that used to be my go-to-source for Mobil One due to their cheap cost.

GTSMeister

Wowser... Not to stir up too much controversy I just gotta say that if you use any of the M1 products with the A40 approval you should be good to go. The lubricating oil industry constantly changes formulations and uses different ones in different parts of the world. Note that one of your data sheets is for an Australian product. As you'll find if you dig deeper you can immerse yourself in it all at bobistheoilguy forums if you choose to.

I used to do that thinking that with 15 years of working for Mobil customer service labs in NJ I'd have something to contribute but net-wisdom prevails and rational thinking is dismissed even when you identify yourself.

I suggested in another thread here (on tappet noise) going to a 5w-40 oil and got ripped for that but then we find out that there is in fact a 5w-50 M1 A40 oil. So I think I'll just leave it as to each their own.

My plan is to continue to use analysis results and to use an oil that meets manufacturer approvals. This way I know what's going on and I'm staying within the warranty parameters of the vehicle. This has worked extremely well for me over the last 45 years.

StormRune

I'm not recommending you change anything you do, but just providing info for those that might be interested. I don't understand the comment about "net wisdom" if you are referring to my posts, I am referencing info from Mobil 1 sites, other respected sources like bobtheoilguy like you mention, and data reported directly to me from Blackstone. I'm not making up anything.

Actually, my switch to 5w50 and the new attempt at the 0w40 Euro from the "normal" full-synthetic 0w40 found in the US was due to my last Blackstone report calling out that my viscosity was markedly too low after just 4100 miles, a reading of 61.1 when the recommended minimum is 70 (as is shown in the history of the report I attached earlier). That's seems like a big delta to me. So I am adjusting based on the analysis results just as you recommend.

The reference to the Australian sheet was necessary since the North American site doesn't list that oil, but in the details there you will see that it calls out it is both the Rest-of-World 0w40 and the North American 0w40 European Car Formula. So that isn't just an Australian product, it is the one sold in North America too.

Churchill

You definitely don't need to change your oil before or after every autocross. If you're regularly doing DE's or AX, then change the oil more frequently (4K or 5K rather than 10K). Oil is degraded by time and mileage far more than it is by the intensity of use. Before every event is a complete waste of time and money.

scadams

The service reminder in my car is set at 20k miles because of Durametric. I still do regular service every 10k miles though so it’s not a big deal.

Greg D.

I've been surprised at how quickly our pricey synthetic oil comes out dirty. I've recently done a 2500 mi oil change (too soon but with the idea to change brands to Motul) and the Mobil 1 was already very dark. Doesn't mean it was bad but it turns dark fairly quick I guess... I used to change oil every 3000 mi on my oldies, so 5000 on the new car doesn't bother me and my old SC got to 250K miles and as far as I know is still ticking on its original engine, so frequent oil change is good.. Easy job. What bothers me is having to measure the output carefully on the 991 because the car doesn't give me an oil level reading for several days (but we've covered that before).