Part 3/5:
To have a better understanding of what needs warming up in a vehicle, it’s essential to know that the main focus should be on the piston rings. Unlike oil, which remains stable under various temperatures, the piston rings can expand and contract with heat changes. When cold, these rings have slightly more clearance, leading to potential combustion gas blow-by. This blow-by can introduce combustion gases into the engine's upper regions, where they may cause carbon build-up and other complications over time.
While it’s important to ensure the engine runs properly, the key is finding a balance between warming it up and not allowing it to idle excessively with low oil circulation, which could cause damage.