Scott - Internal combustion engines produce a tremendous amount of water vapor, most of which you never see.

Mike lives in a warm climate, so he sees little. Here in Massachusetts, we see plenty of it all winter, but it gets less visible or not seen at all when your engine warms up.

On really cold nights, below zero for instance, you can see it coming out all the time, even at speed on the highway if someone is behind you to light it up.

If you are losing coolant mysteriously, you should seek professional help, otherwise your water vapor is most certainly benign.

I would say it's normal. You're running a larger exhaust than the other cars you're seeing, and at a higher temperature too, due to the 16psi... As your exhaust cools after driving, water condensates inside, and evaporates off again as you heat it back up.

-Paul Demeo
1990 780T

water vapor in the exhaust is a natural occurance. Among other things, water is a by-product of combustion. This occurs in very small amounts though. But it is a sign of a clean running engine. It's a good thing in my opinion. I think what is happening is the exhaust system is just not heating up real fast and the water vapor is condensing inside, then steaming out with the exhaust flow. If your engine coolant is droping mysteriously then you could have a head gasket, or turbo water line problem. But if thats not the case then I would not worry about it.