Eli5: how come when you start your car in the cold, it “smokes” but when it warms up it stops “smoking”? The temperature outside never changed

Question

Edit: I’m talking about condensation

In: Physics

Answer 1

Many correct posts below about it being most warm vapor hitting the cold air.

Here’s some more exhaust tips. If exhaust smoke is white and sweet smelling, it’s likely coolant getting into the combustion chamber, likely from a cracked/warped aluminum head, usually from an overheating event.

Blue smoke in exhaust is oil in the combustion. If it’s a small puff only during the first few minutes of running, it’s likely to be worn valve guides in the heads of the engine. If you occasionally clean the spark plug tips, they can run a very long time like this. Only remove plugs when the engine is warm and use a tiny amount of never-seize on the threads when you re-install the plugs.

Blue smoke all the time is most often worn piston rings allowing a steady flow of oil into the combustion, engine will not last long.