Why change engine oil?
• Contamination • Oxidation • Moisture (for every gallon of gas burned we make 1.25 gallons of water Contamination, oxidation and moisture are all affected by trip length and the amount of time an engine spends at full operating temperature. Conservation of resources has driven the movement to extend oil change intervals but the “payback” assumes that a customer will not have to replace an engine prematurely. The environmental cost of an engine replacement – manufacture, installation, disposal of the old unit – exceeds the savings offered by extended drain intervals. On a four-to-five quart sump if every trip (from startup to shutdown) is 30 minutes long or longer in the summer and 45 minutes long or longer in the winter then we can determine your best interval by oil sampling. To determine your optimum change interval several samples will be needed at a cost of about $50 each (including total acid and total base sampling which tells us true remaining oil life.) If every trip is not 30
