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Z06 owners at corvette forum are reporting that the super car 5w50 also loses viscosity at around 3k. Per oil samples sent to blacstone.
Interesting, I wonder if it's any worse than 5w50 FS X2? Since we are starting with a slightly heavier oil than factory fill, a slight loss in viscosity might be OK as long as its ending up more like a 40 weight.
I have yet to do an analysis of my new-to-me 991.1 GT3. However, the car is at the dealer right now getting a G6 put in.
I think its clear that M1 0W40 is not a great oil choice for GT cars, especially the 991.1 with the FF wear risks. I live in Florida so high temps compound the M1 0W40 shear issues. I run Mobil1 FS X2 5w50 in my 981 cayman that is tracked. I will likely switch to that after engine break-in on the 991.1 when I get it back and run it until the engine warranty ends in January.
Once the warranty is up, Mobil 1 Supercar 5W50 is something that caught my eye. It's designed for the C8 Corvette Z06. Here's a quick blurb from an article describing the Z06 valvetrain:
Nice thing too, is Mobil 1 Supercar 5w50 is now relatively cheap and easy to find (Amazon/Online).
Sure sounds awfully familiar... if you remove LT6 from that paragraph you'd think they were describing the 991.1 GT3 engine. GM must have gotten some inspiration (and maybe overlooked the FF failure issues Porsche had to deal with, whoops)
Here is a comparison of the two 5W50 Mobil1 Oils from BITOG forums
Seems the additives in the GM "Supercar" version of the oil have more additives specifically for the sake of protecting the valvetrain (extra Molybdenum and ZDPP). Compared to the Mobil1 Porsche oils, they did not appear to be formulated for the GT engines at all and were shared with all of the other Flat-6 motors that revved lower and didn't have the temperamental valvetrain (I understand there is the new 0W40 C40-GT spec oil, but it doesn't look much better on paper than the old standard A40/C40 spec oils did).
Not sure if it makes sense to switch to this, but either way it's interesting that GM seemed to put more thought into oil formulation for their high revving engine with finger-followers than Porsche did. By no means am I saying that the FF wear would have been solved by oil alone, but I'm sure that didn't help the situation.
I can confirm Mobil 1 Supecar5w50 was specifically designed to protect DLC coating on the valvetrains. It was compared to 5w50 FSx2 as well as ESP and ESP X3. The base oil and additivites are better. They will work well in GT3 Engine for finger follower wear. I am running Mobil 1 Supercar5w50 now in my 991 GT3 RS. I'll post the oil analysis eventually. I just dumped FS x2 5w50 and sent it off for oil analysis, both to Blackstone and the engineers that developed 5w50 Supercar. I will share when it comes back.
5W50 oils will shear more percentage wise than say a 0W40, but the most important factor at the end of the day (HTHS) is still higher for a worn 5w50 oil or close to a new 0w40.
Today, 02:30 PM
