I hate Dexos
Safety Car
Joined: Jan 2015
Posts: 3,941
Likes: 499
From: Northern Virginia
Drifting
Joined: Jan 2005
Posts: 1,942
Likes: 1,328
From: Houston Tx
[QUOTE=AUTO_X_AL;1591025831]
That’s an interesting oil. In all respects but one, it’s great. With the ultra wide spread of 40, it does a pretty good job of spanning the cold start and normal street driving behavior of 5W30 while giving nearly as much track temperature protection of 15W50. The fly in the ointment is that to get that high a spread, it must use a lot of VI improver. If you’re willing to trust claims that VI improver is much more stable these days and/or if you’re willing to change your oil every three to five thousand miles in case those claims are optimistic, it might be your best choice.
It does leave you a bit exposed on warranty issues since it’s neither Dexos nor mentioned in the owner’s manual. But 15W50 isn’t Dexos either, even though it’s mentioned in the owner’s manual. GM probably shied away from mentioning 0W40 in the owner’s manual because of concerns over the large amount of VI improver needed to reach that ultra high spread, so if you do use it, document that you’ve changed it often, and maybe once or twice, send used oil to Blackstone to document that the viscosity held up at the intervals and severity of service you were using. Obviously, I can’t even come close to promising that would be enough to satisfy GM in any kind of warranty dispute. I’m just trying to think of what they might throw at you, and what you might throw back. The fact that the GM engineer mentioned it to you in the first place might also be a point in your favor.
It does leave you a bit exposed on warranty issues since it’s neither Dexos nor mentioned in the owner’s manual. But 15W50 isn’t Dexos either, even though it’s mentioned in the owner’s manual. GM probably shied away from mentioning 0W40 in the owner’s manual because of concerns over the large amount of VI improver needed to reach that ultra high spread, so if you do use it, document that you’ve changed it often, and maybe once or twice, send used oil to Blackstone to document that the viscosity held up at the intervals and severity of service you were using. Obviously, I can’t even come close to promising that would be enough to satisfy GM in any kind of warranty dispute. I’m just trying to think of what they might throw at you, and what you might throw back. The fact that the GM engineer mentioned it to you in the first place might also be a point in your favor.
Drifting
Joined: Oct 2005
Posts: 1,729
Likes: 62
From: South Lyon MI
Originally Posted by meyerweb
I'm surprised. I used to autocross a Miata fairly seriously, and oil temps would spike to about 220, but settle back down quickly when the run was over. I guess our 'vettes are just hot blooded.
Tracking will hit that 250+ mark. I've yet to have any issues using what I have so far.
The 0W40 sounds great in theory. I'll see what's going on at the PRI show next week. That should have all of the latest and great racing products.
