Originally Posted by
Discodicky
Not at all.
Without fail, in my 31 yrs experience, oil samples showed classic cases of the engine oil at 250 hrs was right near the end of its life.
This was prior moving to 500 hr intervals however the results were not much better at 500 hrs even with the increased sump capacity.
Zinc or magnesium (additives) would be almost depleted; iron, and lead, copper would be starting to rise (pistons, brgs, etc)
Silica (dirt) could be rising, sulphur could be up.
Silica is also sometimes used as an additive and it was possible to have the parts per million (ppm) steady, insofar as the silica (as an additive) would be depleting, but the silica (dirt via the air filter) would be increasing thus causing it to remain somewhat steady.
The key point about oil analysis is to monitor the TRENDS over a period of several samples via engine hours/vehicle klms, ie, if the (bad) results such as iron increasing, are trending upwards and thus pointing towards wear or failure of a component.
If sulphur is rising then you might have a weak head gasket or "O" ring somewhere.
There is a lot to oil analysis!