🔍 Key Concepts

• Piston ring types: compression rings vs oil control rings • Typical location of the oil control ring on a piston • Visual features of an oil control ring, such as drain slots/holes and a different ring profile

💭 Think About

• Look at the relative position of each labeled ring from top to bottom of the piston and recall where the oil control ring is normally installed. • Compare the shapes: which ring looks designed to scrape and return oil to the crankcase rather than seal high combustion pressure? • Notice any extra grooves, slots, or spaces that would allow oil to flow back after being scraped from the cylinder wall.

✅ Before You Answer

• Verify which ring is closest to the piston skirt (furthest from the crown). • Check which ring has a design suited for draining oil, not just sealing gas pressure. • Confirm that the chosen ring matches what you have seen in typical three‑ring piston arrangements: two compression rings and one oil control ring.