What Does Soot Represent in UOA Tests , Any Help on This ?

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Aug 4, 2002
Ontario , Canada
I just received another UOA, comparing different vis. Redline oils. Most readings were very similar if not the same. One big difference however was the Soot count and sulfation counts. In the first 5w-20 Redline Oil UOA the soot count was 14 and sulfation was 18 (dunno if this is ppms or %) , in this last Redline 10w-30 UOA there was 0 soot and 0 sulfaton. Found that strange.

One thing changed between runs was the intake system - Silicon counts went from 15ppm to 11ppm from paper to foam filter. Does this affect soot count. I even left the oil filter in place over the two intervals - I did not change the oil filter as the intervals were fairly short and I was running low on the Redline Oil in my possession and could not purchase additional supplies in time for my planned roadtrip which was the next day.

So just wondering what affects soot and sulfation readings/counts.
Any help would be appreciated. thanks


[ July 10, 2003, 07:16 PM: Message edited by: Idrinkmotoroil ]
Soot is the percentage of soot that is being suspended in the oil. Soot comes from the exhaust gases.

Silicon mostly comes from dirt entering the motor. High Si is usually a sign of poor air filtration.
Soot in our in-house kits for a gas engine measures solids, in a diesel will be fuel soot.

Depends on the method used to read soot. If there is a seperate solids reading focus on that for comparison.
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