Mobil 1 15W50, 1178 mi OCI, 23.4k mi, C7 Corvette Z06

[Emperors6]

All mileage is in kilometers not miles. Notes from oil slip: "Short OCI since we did some power upgrades and had to do an oil change. Probably doesn't need UOA, but might as well check." The OLM was at about 86%. Previous fill was Mobil 1 15W50. Next fill is AMSOIL Dominator Synthetic 15W-50 (going back to Mobil 1 15W50 after).

FYI the fuel in this OCI might be due to the over-pressurized crankcase that blew the front main oil seal. I installed a 15% overdrive pulley but turns out we generated too much boost for the seal. We went to a bigger supercharger, Kooks headers + green cats, and catch can afterwards. That will be next OCI after some track time.

The previous OCI is not actually showing correctly in the report, but it's in this thread.

 

[blingo]

Are you seeing blower boost escaping via intake valve guides, more than the PCV can cope with? That's not to be expected, is it?

 

[Emperors6]

Well we upgraded it with a catch can that vents on over boost now so it's fine. It felt great on the track yesterday, but one of the coil wires got a bit burned so we had to replace it since I was getting misfires on one cylinder. I'm going back today to test some more.

 

[Gene K]

Not to alarm you but in my opinion that cars got lots of fuel.

In the study I saw with a Euro Spec 5W-30 Synthetic (3.5+ HTHS) 3% Fuel Dilution with 95 RON Gasoline resulted in a 36F drop in Flashpoint. 5% resulted in 54F.

M1 15W-50 has a virgin Flashpoint of 450F so you have a 75F Drop. You might consider someone that does an actual Fuel Dilution Test with Gas Chromatography for the next analysis.

 

[Emperors6]

Thanks for the info. I have a pretty good idea of the cause of the fuel dilution and based on a previous M1 15W50 OCI it's about a 45F drop in flash point. I'll see what happens at the next OCI.

 

[Deleted member 89374]

@Emperors6 Well, looking at the MSDS for the Mobil 1 15W-50, there is no way of telling what kind of base oil ExxonMobil used to make it. The Mobil 1 FS X2 5W-50 follows is made in a similar fashion to the FS 0W-40, which is a bit of PAO and mostly GTL base stock. So I doubt that it would be an improvement to go to Mobil 1 5W-50 in your case. It seems like you are enjoying your vehicle and are running it hard. There is absolutely nothing wrong with that. Just my two cents, however, I would go to something like Red Line Oil 5W-50. You will get an oil made from PAO+Ester with a very nice additive package with more ZDDP than you get in the Mobil 1 oils, and more anti-friction additives like Moly, not to mention like more detergents like Calcium. The PAO+Ester base oil can withstand more heat as opposed to other inferior base oil blends. You want to minimize wear in that engine while running it hard, and IMHO this is the only way to do it. Also, Mobil 1 claimed that there are 1200ppm of Phosphorus and 1300ppm of Zinc in the M1 15W-50. According to your UOA, that's nowhere near reality. They could be lying. Check it out here: https://www.mobil.com/lubricants/-/...hash=B478EACF4BAC5D7B9A3D33763B53E67669592EE5

 

[Gene K]

@Emperors6 Well, looking at the MSDS for the Mobil 1 15W-50, there is no way of telling what kind of base oil ExxonMobil used to make it. The Mobil 1 FS X2 5W-50 follows is made in a similar fashion to the FS 0W-40, which is a bit of PAO and mostly GTL base stock. So I doubt that it would be an improvement to go to Mobil 1 5W-50 in your case. It seems like you are enjoying your vehicle and are running it hard. There is absolutely nothing wrong with that. Just my two cents, however, I would go to something like Red Line Oil 5W-50. You will get an oil made from PAO+Ester with a very nice additive package with more ZDDP than you get in the Mobil 1 oils, and more anti-friction additives like Moly, not to mention like more detergents like Calcium. The PAO+Ester base oil can withstand more heat as opposed to other inferior base oil blends. You want to minimize wear in that engine while running it hard, and IMHO this is the only way to do it. Also, Mobil 1 claimed that there are 1200ppm of Phosphorus and 1300ppm of Zinc in the M1 15W-50. According to your UOA, that's nowhere near reality. They could be lying. Check it out here: https://www.mobil.com/lubricants/-/...hash=B478EACF4BAC5D7B9A3D33763B53E67669592EE5

Yogi you might want to compare some of the Blackstone results to PQIA results. It might be enlightening.

 

[Deleted member 89374]

Yogi you might want to compare some of the Blackstone results to PQIA results. It might be enlightening.

I think I know where you're going with this I will as soon as I have a minute, thanks

 

[Impatient]

Are inhaled oil analysis fumes hallucinogenic? How is 25 ppm at 1900km “better than last sample” which was 14 ppm at 9600 km? With all the fumes and low viscosity oil residue on their fingers, it’s possible this was just a slip on the keyboard...or a slip of the mind...or am I the one hallucinating? Well, checking the math further, perhaps the interval I should have read 2808, but even then, the Blackstone comment makes no sense.

 

[Emperors6]

There was a hiccup in their system and it doesn't show the previous sample. You can see the previous sample in this thread: https://www.bobistheoilguy.com/foru...0-566-mi-oci-22-1k-mi-c7-corvette-z06.331002/. Look for the 05/28/2020 sample date.

 

[Impatient]

Okay, that makes sense now. thanks. If I could remove my previous post I would.

 

[Emperors6]

No worries.

 

[benjy]

yes another poster just did a virgin analysis + brackstone noted 1330 of zinc i believe!

 

[loneryder]

All mileage is in kilometers not miles. Notes from oil slip: "Short OCI since we did some power upgrades and had to do an oil change. Probably doesn't need UOA, but might as well check." The OLM was at about 86%. Previous fill was Mobil 1 15W50. Next fill is AMSOIL Dominator Synthetic 15W-50 (going back to Mobil 1 15W50 after).

FYI the fuel in this OCI might be due to the over-pressurized crankcase that blew the front main oil seal. I installed a 15% overdrive pulley but turns out we generated too much boost for the seal. We went to a bigger supercharger, Kooks headers + green cats, and catch can afterwards. That will be next OCI after some track time.

The previous OCI is not actually showing correctly in the report, but it's in this thread.

Why are the Phos and Zinc values so different from the virgin sample posted at the same time??

 

[Emperors6]

Which sample is that?

 

[alarmguy]

Why are the Phos and Zinc values so different from the virgin sample posted at the same time??

Im completely confused by this thread and having a hard time believing it because I am seeing so much confusion in these reports.

Im sure I am missing something here by why am I looking at two different UOA sheets that I think are being represented on the same engine yet one sheet is dated 8/20/20 and the other 8/21/20?
Im not in anyway saying the OP is misleading anyone, Im just trying to figure it all out, only because I posted a UOA on the same exact oil and its the first or second post in the motorcycle UOAs right now.
*LOL maybe I didnt have enough coffee today ...

But, I seem to be looking at two completely different pages of UOAs yet the date that Blackstone did the UOA is only 1 day apart in the same month and year?

 

[Emperors6]

There was some confusion with Blackstone since I sent multiple oil samples at the same time for the same engine, but they didn't process it in chronological order, but in the order they received them. So, in this thread the 5/28/2020 sample is missing in the picture for the first post, but it's available here: https://www.bobistheoilguy.com/foru...0-566-mi-oci-22-1k-mi-c7-corvette-z06.331002/.

As for the 8/20/20 and 8/21/20, those are the report dates. I think you are confusing the report date with the sample date. The report date is when Blackstone processes the sample. Sample date is when the sample was actually taken as reported by me.

For the VOA UOA, I think this is the thread being referred to: https://bobistheoilguy.com/forums/threads/mobil-1-15w50.340775/. I'm not sure why the Phosphorus and Zinc readings are around 20-30% off. A tribologist would have to comment, if it's possible due to: contamination of the sample, chemical reactions while the oil is in use, differences in production tolerances of the oil, measurement differences due to the procedure used by Blackstone. I simply do high level comparisons if something is in the ballpark (i.e. orders of magnitude difference) as well as look at the wear metals. The additive package I pay less attention to, as long as it's there. One possibility is that before this run I ran M1 5W30, and there's usually 2-3 quarts out of 10 quarts that's left behind in the oil cooler when I do an oil change.

Blackstone did produce a new report that had the right chronology. I'll include it here to make it easier: