In my early days of airplane ownership, I might have been naive by today’s standard when it comes to engine oil. But it was stone simple—I flew my airplane, it needed oil, I bought some and changed it. Repeat.
Today, web forums are packed with endless threads where owners fret about filters, additives, change intervals, high use, low use, whether to dump it at 25 hours or 50 hours, whether to pour multi-viscosity or straight weight, use an additive or not, pay for a lab analysis or just visually inspect the screen or filter, use semi-synthetic or mineral and the idea of mixing viscosities. Let’s take a step back and review some basics in part one of this discussion on oil.