I see this alot when I'm driving around, almost always on newer cars and was wondering what it was. The obvious answer to me seems to be unburnt fuel. That seems weird to me, but what else could drip out of a tailpipe?

Condensation.

I see this alot when I'm driving around, almost always on newer cars and was wondering what it was. The obvious answer to me seems to be unburnt fuel. That seems weird to me, but what else could drip out of a tailpipe?

Condensation / Water Vapor is what I was told when I asked that question before. Hope this helps.

If it was unburnt fuel, you'd know about it by an extremely loud exhaust backfire and a cool looking flame shooting out your tailpipe. No, it's just water...not vodka or gin as I had once hoped for...but don't put your mouth on your tailpipe for a drink anyway. :lol: How do you think I found out it wasn't vodka or gin? 8O

Water from the tail pipe is a good and bad thing. It's good because it means complete combustion. It's bad because it rots out exhaust systems from the inside.
If you take your high school chemistry book out (if you can still find it) you can do a little gozinta's and see the internal combustion engine makes water if efficient enough.

If it is usually when it's cold or in the mornings it's dew or condensation. I've seen that same thing but i also notice it from older cars. It also matters if it is carbuerated because they have to warm up and usually i get rid of any condensation when sitting in the drive way when its cold. Injected cars just start up and go; therefore you are more likely to see coming from new (injected) cars.

Combustion/Oxidation of Fuel/Hydrocarbons:

HC + O2 --> C02 + H20

Fuel + Oxygen from Air ---> Carbon Dioxide + Water





Q. What are two very common things used are fire extinguishers?
A. CO2 and H2O

yeah id have to concure with what has been said... if it was unburnt fuel you would notice the deafening back fires.

It's one reason why they make weep holes in mufflers so they hopefully won't rust out. If you run the engine long enough the heat produced will vaporize the water and the steam produced will evacuate the system. Good theory, but similar crap is produced when the system cools after running hot enough to clean it out. It's a vicious cycle. :cry:

The liquid coming from the tailpipe is water both from condensation and the byproduct of combustion. Since sulfur dioxide is also a byproduct of combustion the liquid is an mildly acidic.