Is it normal for a used engine oil (after 5000km) to have high iron (23ppm), copper (18ppm), aluminium (8ppm). I know it's supposed to be due to engine wear, but how high is considered high? Any limits that I can refer to?
What about increase in magnesium (increase of 400ppm) and calcium (increase 80ppm)? Aren't that supposed to be additives and should be depleted?
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