Recent content by JAG

Are there new forum rules that I’m unaware of allowing moderators to assign homework and try to hold the assignees accountable?

I agree that it has significant errors. What’s your answer to my virgin and used oil question? I’m asking for an educated guess. I don’t expect you to gather and analyze the data.

I appreciate the information the OP provided. It didn’t come from a thorough set of tests backed with statistical analysis and I don’t require that. If it did tell us absolutely nothing, average flashpoint on a large set of virgin oils from Blackstone would not be significantly different from...

Visible-sized water droplets in oil are very resistant to evaporation and forming emulsions in stationary hot oil that is < 100 C. If the oil and water droplets undergo shear, it increases the emulsion tendency, which allows for increased water evaporation rate. If a water droplet gets hot...

Friends don’t let friends use Blackstone. Use a company that uses much more accurate fuel dilution test, like Oil Analyzers Inc. and many other companies use. If you want a more viscous oil to counteract the thinning effect of fuel, use Mobil 1 ESP 0W-30. Valvoline Restore and Protect is also...

I didn’t notice anybody mention the 4.2 cP HTHS and 14.3 cSt viscosities, but it’s relevant so there it is. I’m glad that Hohn is experimenting and sharing the outcomes. More hard data would be nice, like oil temperatures and pressures, drain plug magnet residue, and volatility. I suspect that...

I am almost certain that Pennzoil Ultra Platinum 5W-20 is significantly less volatile than the 0W-20 grade. I’m also moderately confident in saying that line of oil does not use lower quality base oils in some of the viscosity grades. Mobil 1 ESP 0W-30 contains esters and I think that is why...

The varnish talk got me thinking about how most people think that only the similarity of polarity between two substances determines their ability to form a stable mixture and for dissolving to occur. However, there are two other important properties, shown in the quote below, of both substances...

I think it’s close to impossible to answer many of those questions, partly because there is considerable variability in properties within regular Group III oils, within GTL oils, and especially PAO oils. Even with specific oils identified, unless the person is an experienced tribologist or the...

In the early 2000s, I had a low mileage, Subaru Impreza RS that was ~1 year old. The manual transmission oil was NOT leaking with the factory oil. I changed it to Red Line MTF and the leaking was rapid enough to drip onto the exhaust. After that mess happened, I changed it to some more...

It is actual engine usage, so it doesn’t even have a need to represent what matters; it is what matters. However, unless parts are disassembled and completely cleaned between different oils used, it does not provide direct, comparative data related to deposit or deposit precursor formation. It...

Oh, I apparently made a typo in the post. The label in that picture is correct. It is 5W-40, from the PCMO series. I have not posted a picture of the 5W-30 Euro and it’s not on this phone, so it is inconvenient to dig up now.

Neither the OP nor I have said that we expect some HPL oils perform poorly in preventing deposits in actual modern turbos. His and my tests are too different from TEOST Turbo to make that claim, in my opinion. This thread is about the discolorations in the OP’s engine and the test results.

I too think higher volatility usually tends to increase engine deposits, but if the thin-film test does no replenishment of oil to the site, then it loses that critical factor in engines where replenishment does occur, even if it is a spot that sometimes gets lucky for a splash of oil to land on...

Hohn, varnish on the sides of the cup walls occur. You can see that in the post right below the one I linked above. It also occurs on the bottom of the foil that covers the cups, but I never photograph that. I think the blobs do not adhere to the bottom of the cups due to the detergents and...