Which piston ring is primarily responsible for controlling oil consumption?

The oil ring is specifically designed to manage the lubrication and oil consumption in an engine. Its primary function is to control the amount of oil that reaches the cylinder walls. By doing so, the oil ring helps maintain the proper film of oil for lubrication while preventing excessive oil from entering the combustion chamber, which could lead to issues like smoking and increased emissions.

In contrast, the compression ring is primarily responsible for sealing the combustion chamber to maintain pressure during the combustion process. The scraper ring assists in scraping excess oil off the cylinder wall to prevent it from entering the combustion chamber, while the second ring, which is often a compression ring as well, aids in sealing and controlling gas flow. While these rings play critical roles in overall engine performance, it is the oil ring that is specifically tasked with controlling oil consumption.