Soot loading from DI engines - Size of particles

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Does anyone know the typical particle size / range for the Direct Injection soot loading into the oil?

Can't seem to find any information on it.
 
All I know is that gasoline engines will have a particulate exhaust filter and use urea fluid like modern diesel engines do in the not to distant future.
 
I'm not sure you can use the word typical but the below was from a 2015 study from sciencedirect.com that I couldn't link. I've seen other studies with similar information so I think they're out there...

• Soot-in-oil particles extracted from used lubricating oil of GDI engines.
• Soot in oil shows modest branching with average length of 153 nm and 59 nm in width.
• Soot spherical primary particles of 10-90 nm form the agglomerates.
• Primary particles exhibit an amorphous shell structure of 5 nm.
• Volatile structures were found to be deposited onto the surface of primary particles.
 
Originally Posted by Vuflanovsky
I'm not sure you can use the word typical but the below was from a 2015 study from sciencedirect.com that I couldn't link. I've seen other studies with similar information so I think they're out there...


I wasn't able to find any information so that's why I said typical as I was unsure at this point but assumed there might be a typical size or range sort of thing. Thanks for the info you provided.
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I'm guessing with the particles being too small to filter, that oil changed more frequently would be better than other factors like brand / add package etc. to limit the abrasiveness over time.
 
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Originally Posted by skyactiv
All I know is that gasoline engines will have a particulate exhaust filter and use urea fluid like modern diesel engines do in the not to distant future.


Are you talking about the skyactiv-x HCCI engine? I don't remember that being mentioned during the tech reveal.
 
Yeah, I'm no scientist but I'd speculate that these particulate size figures and content could vary based on several things...so apples to apples comparisons might be difficult.

I've seen distinctions between wall-guided and spray-guided GDI and references to more ethanol content generating more water-insoluble matter than fuel with lower ethanol content, etc. I'm sure if differences like those aren't controlled versus some other study you'd potentially have to be aware of what you're looking at to a more significant degree than a typical layman.
 
Diesel engines put enormous amounts of soot in their motor oil. I note that Chevrolet now recommends Mobil 1 0-40 ESP for the DI Corvette. This oil is a Dexos2, the "diesel" Dexos.

When I change the oil in my DI Corvette, the used oil does not look particularly sooty.
 
Just as in the Corvette noted above, the oil in my Golf All Track, a 2017 DI engine, does not look particularly sooty but then I have been changing the oil (see signature) at 5000 mile intervals. I do see soot in the tailpipe, however. I run this car on mid-grade Exxon fuel with an occasional fillup with 93 octane if I am travelling a good distance at speed and/or through mountains. This engine responds very well to the mid-grade and higher octanes.
 
I think with gasoline engine particles in DI engines being so tiny as noted above you would really have to be running it for a while to notice it in amber coloured oil and by then a lot of damage could be done because they are really abrasive when the numbers get too high.

This is why I wanted to know what the size was because I was hoping filtration would be able to take care of it but I think it's just going to have to be shorter OCI's. Although Toyota says 10,000 miles (16,000km) is acceptable in normal use so...
 
Yeah I don't doubt it is. Even Diesel fumes pre particulate filters was known to kill people earlier that lived near busy roads like interstates / highways.
 
Originally Posted by StevieC
I'm guessing with the particles being too small to filter, that oil changed more frequently would be better than other factors like brand / add package etc. to limit the abrasiveness over time.

You could always jump up a grade or two, and go by the diesel mantra, as thick as is possible, as thin as is necessary. Sorry, couldn't resist.
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"As thick as possible" Referring to the diesel owners that have the big pipes and like to fog all the black smoke out of them?
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Yes, and then you see soot. I've seen black liquid dripping out of their exhausts at times, and given these were at operating temperature, I'm guessing that's soot laden fuel, not soot laden water, but one never knows.
 
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