Originally Posted by NotAPreppie

Does the cloud hang in the air for several minutes, growing the whole time or does it stay small and localized to a foot or two around the tail pipes?

Originally Posted by NotAPreppie

Seems normal but maybe you should post a video of it to be certain.

Does the cloud hang in the air for several minutes, growing the whole time or does it stay small and localized to a foot or two around the tail pipes?

Combustion produces a lot of H2O. When the engine and exhaust system are cold, the water vapor condenses out into white clouds, likely even before the exhaust gasses leave the tail pipes. After things warm up, the exhaust gasses have time to spread out and expand before the water condenses out so you don't get the cloud.

This is compounded by the fact that there is always a little bit (or sometimes a lot) of water condensed inside the muffler. This causes the air inside the exhaust to be saturated with water (making condensation happen at higher temps) and adds mass (causing the exhaust system to take longer to heat up).

Originally Posted by New Yorker

With mine (0-20ºF, car's been sitting outdoors for a few days) there are big, white billowing clouds of smoke pouring out of the exhaust pipes and hanging in the air for many minutes. If you happened to drive by and not know cars, you'd probably think something was wrong. It's quite dramatic. But, as I said, it's apparently nothing.

Originally Posted by NotAPreppie

That's kind of crazy. My garage is detached and unheated but even at 0F, I never had anything like that.

Originally Posted by NotAPreppie

If the water seals were gone, you'd probably notice a drop in your coolant. Also, it would smell like coolant (sometimes described as smelling like maple syrup).