What is the primary purpose of the oil control ring in an engine?

The primary purpose of the oil control ring in an engine is to prevent oil from entering the combustion chamber. This ring works by scraping excess oil from the cylinder walls back into the crankcase while allowing just enough oil to remain for lubrication. If oil were to enter the combustion chamber, it could lead to undesirable effects such as increased emissions, lower engine performance, and potential fouling of spark plugs.

In contrast, the other options touch on different aspects of an engine's lubrication system. While increasing oil pressure, regulating oil supply to bearings, and improving engine cooling are all important functions within engine operation, they serve distinct purposes separate from the specific role of the oil control ring. The oil control ring's function is crucial for maintaining optimal combustion conditions by ensuring that the right amount of oil is managed, thereby contributing to the overall efficiency and longevity of the engine.