Don’t get caught up in trying to predict how an engine is wearing based on a UOA, it’s really not that simple and takes a lot of training and experience to do that accurately. In this case it’s showing 47 parts per million of iron, but what does that really tell you? Is it from true wear, and if so, where did it come from? The timing chain, crankshaft, cylinders? Or is it from corrosion or a chemical reaction between the oil and metal surfaces? Inexpensive UOAs like the ones from Blackstone are limited by the equipment they use to only “seeing”particles in a certain size range, I’ve seen 1-5 microns and 3-5 microns from people who are very experienced with these tests so larger and smaller particles go undetected.
New engines tend to show higher metals until they’re broken in, and it’s really difficult to know when “break in” is over.
UOAs can be very useful in checking the oil for contaminants such as fuel, water, antifreeze and silicon (dirt). The lab can also provide the TBN (total base number) which helps determine if the oil still has some service life left or if it’s no longer able to neutralize acids in the oil and needs to be changed. The TBN is helpful in determining what the proper OCI is for a particular vehicle and driving conditions.
