What amount of vacuum should each cylinder be pulling?

Each cylinder in an engine typically pulls a vacuum between 17 to 22 inches of Mercury (inHg) at idle, depending on the engine's design and condition. A higher vacuum reading usually indicates good engine health and efficient air-fuel mixing, while lower readings can signal issues such as leaks, poor valve sealing, or other mechanical problems. Monitoring vacuum levels can be an important diagnostic tool for assessing engine performance.