Which is a common cause for high oil consumption in engines?

High oil consumption in engines can be predominantly attributed to worn piston rings. Piston rings are crucial components that help maintain the proper seal between the combustion chamber and the crankcase. They control oil usage by preventing excessive oil from entering the combustion chamber, where it would burn off.

When piston rings are worn or damaged, they cannot effectively seal the cylinder. This allows oil to slip past the rings and enter the combustion chamber, leading to higher oil consumption. Additionally, worn rings can cause a loss of compression, resulting in reduced engine performance.

While splashing oil onto cylinder walls may seem like a potential cause of oil consumption, it is not a primary factor. The engine's design already accounts for oil lubrication, and oil splashed onto cylinder walls typically does not contribute to excessive consumption unless other issues (such as ring wear) are present. Therefore, worn piston rings are a more common and significant contributor to high oil consumption.