Predetermined oil intervals and what to check in oil analysis

Updated Feb 10, 2021
Oil analysis is the best way to keep track of how your engine is wearing.Oil analysis is the best way to keep track of how your engine is wearing.

As a responsible truck owner, you should change your oil at predetermined intervals. Oil analysis provides great information and is the best way to keep track of how your engine is wearing.

The two items I eyeball in the oil are the iron and silicone, which is ingested dirt getting past the air filter(s); these two contaminants will wear out the engine quickly. I prefer to see iron at 20 parts per million, but that’s a conservative number, and I can live with 60 ppm, which would come at about 50,000 miles. Going 200,000 miles on engine oil is out of the question in my book.

In oil analysis, we also look at the levels of:

  • Chromium, which is piston ring wear;
  • Lead, which comes from the main and rod bearings;
  • Copper, which comes from bushings, bearings and thrust washers;
  • Tin, coming from bearings and bushings again; and
  • Aluminum, which comes from some pistons, bearings and thrust washers.

Oil is the lifeblood of the engine, and you shouldn’t let it get too dirty. Mechanics get to see inside the engines, and every mechanic I know changes their oil frequently – and that is on a pickup or family sedan. Do your engine – and your wallet – the service of ensuring you change your oil when you should.

-Bruce Mallinson is the owner of Pittsburgh Power, an engine performance shop in Saxonburg, Pa.