No. Do not use car motor oil.
Car oil is not formulated for chainsaw bar and chain lubrication. It lacks the tackifiers that make bar oil stick to the chain at high speed. It will sling off, causing rapid chain and bar wear, overheating, and increased risk of kickback. It can also damage the oil pump seals.
Use only a dedicated chainsaw bar oil. In a genuine emergency, a biodegradable vegetable oil is a better temporary substitute than motor oil, but performance will still be poor.
If you're asking because the oiler seems clogged, that's a different fix. Clean the oil outlet on the saw and the bar groove. Use only proper bar oil to prevent future clogs.
Heads up: The right oil is a safety feature. A poorly lubricated chain binds, kicks back more easily, and can snap. Keep a bottle of STIHL or equivalent bar oil on hand.