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Per the Tech Q&A column in the December 2020 issue of Panorama, where someone asked about C40 oil for his 2021 GT4:
"Here's the story directly from the proverbial horse's mouth: C40 spec oil is required instead of A40 to protect the gas particulate filters. All 2018 and newer Porsches state that in the manual, but those vehicles (model years 2018, 2019, and 2020) did not come to the US and Canada equipped with the gas particulate filter system, so they could use the A40 spec oil. For model year 2021 and newer, every Porsche imported to North America will be equipped with EPS and requires C40 spec oil.
"C40 oil is not readily available, as you've found out, so you will have to take it to the dealer for oil changes until you can find the new oil. Right now, very few dealers have any of the C40 oil at all, but they should be well stocked before year's end. The new oil has a part number VW5100."
I'm guessing the GPF matrix may eventually clog up or degrade if you use A40 oils, hence the requirement to use C40 even if the GPFs are not monitored. Yet another reason to get rid of them or perform the Big Genitalia Mod.
Per the Tech Q&A column in the December 2020 issue of Panorama, where someone asked about C40 oil for his 2021 GT4:I'm guessing the GPF matrix may eventually clog up or degrade if you use A40 oils, hence the requirement to use C40 even if the GPFs are not monitored. Yet another reason to get rid of them or perform the Big Genitalia Mod.
Don't let Arch here you say this.... my comment in a different thread postulated a similar scenario, I felt that without the active coating on the matrix it could be susceptible to clogging, and it was best to remove the GPF!
Per the Tech Q&A column in the December 2020 issue of Panorama, where someone asked about C40 oil for his 2021 GT4:I'm guessing the GPF matrix may eventually clog up or degrade if you use A40 oils, hence the requirement to use C40 even if the GPFs are not monitored. Yet another reason to get rid of them or perform the Big Genitalia Mod.
If you are at the track a lot this would be good idea to try the Mobile one 5-50. Oil temps can reach 270 degrees in the summer on some cars, especially if there is an aftermarket screen over the radiators. Other Porsches without a center radiator are also vulnerable to this. As the oil cooks, the viscosity breaks down, it gets thinner, and leads to excessive wear. I have been using this oil on my Cayman S for years without any issues. It is Porsche certified (A40) as is the 0-40 weight. I change it out every 6 track days. It comes out golden and clean, but my mechanic and I know that the viscosity is no longer 5-50. We sometimes don't change out the filter if its only been a few months since the last change. This will not be for everyone, but for those who are aggressive with their cars, it will add a little extra protection for your valuable Porsche engine. There are also many other fine brands of upgraded oil such as Motul that one can try, but I prefer using something certified by Porsche.
Last edited by lovetoturn; 12-21-2020 at 09:28 PM.
Well that's a little less than $20/liter but not much. I expect once it gets int6the US distribution system the price will come down considerably. I'm not gunb going to worry about it and if it's not available for my first change at 2000 miles I'll use the A40 I have on hand. One or two oil changes most likely won't hurt the GPF much. Then I can do the delete later on.
Holy COW..... $20 a QUART (Litre)? Absolutely ridiculous. Do we get a kiss, or at least a hug, with those prices since we're obviously getting f.... never mind. It's not a matter of being able to afford it or not - I'm sure every single one of us can. It's a matter of principle. That just isn't right.
Hah reminds me of the good old days with the BMW S54 engine requiring 10w60 @ 15 bucks each. (In the early 2000s)
Well that's a little less than $20/liter but not much. I expect once it gets int6the US distribution system the price will come down considerably. I'm not gunb going to worry about it and if it's not available for my first change at 2000 miles I'll use the A40 I have on hand. One or two oil changes most likely won't hurt the GPF much. Then I can do the delete later on.
Sounds like a plan! Seems like the C40 extras are all about babying the GPF
Yes, I skimmed over the thread. There are some issues on the A40 vs C40 spec oils. The C40 spec limits people to a 0-40 weight on Mobil 1. The C40 basically appears be the newer spec to cover the GPFs now placed in our cars. In North America our GPFs are inactive and do not serve the intended purpose. So it doesn't really appear that the new spec so much applies to our cars. The A40 should be fine as many have said.
For those of us who do visit the track frequently or live in the south, a 5-50 option can still be of value. Just want people to be aware of that and not shy away from it because it does not have a C40 rating. It is a bit more stout and can handle the higher temperatures better.
It also appears most dealers aren't so much aware of the C40 vs A40 issue either. If you take your car to the dealer right now, odds are you are going to get the house special Mobil 1 0-40 from the overhead tap. That should suite your car just fine. For those who want the latest updated spec for their oil and can find it, all the power to you. Just my 2 cents and maybe that's all its worth.
I think you've summed it up pretty well, and I share your opinion. I just received an email from Suncoast advertising their Mobil 1 0W-40 ESP for $10.95/at. It isn't the ACEA C3 spec on the bottle but it says it is for Porsches after 2018, so maybe they just don't have the updated picture. You can go to their website and see for yourself.
Good to read the thread referenced above in the 718 forum - what is further confusing is the cited Porsche document recommending C40 oil for late model 718/992 with or without GPF
Last edited by Mercuriell; 12-22-2020 at 08:06 AM.
Yes, which begs the question, if the A40 oil was good enough before, why all of a sudden is it not? I know oils evolve and better oils are rolled out and recommended for older cars, but if A40 was okay for a 2019 Porsche Cayman and now it's not, then something is fishy. I am willing to bet that virtually every Porsche with a 2019 build date received A40 oil from the factory and the dealer .
12-18-2020, 10:24 PM
my comment in a different thread postulated a similar scenario, I felt that without the active coating on the matrix it could be susceptible to clogging, and it was best to remove the GPF! 
