Motor oil works in a pinch but don’t make it a habit.

Yes, you can use motor oil as bar and chain oil in an emergency, but you’re trading short-term convenience for long-term wear.

Motor oil is thinner than bar oil and lacks the tackifiers that keep it stuck to the chain at high speeds. That means more fling-off, less lubrication, and a chain that wears faster. It also doesn’t hold up as well in heat, so the bar can run hotter and stretch the groove.

The bigger risk is environmental. Motor oil doesn’t biodegrade, so every drop you sling into the dirt or onto plants is a problem. Bar oil is formulated to break down.

If you’re in a genuine emergency—one cut to get home—go ahead. But don’t make a habit of it. Keep a jug of proper bar oil in the shed. Future you and your saw will thank you.