Only you can determine what it is. It could be oil, coolant, water, or gasoline. You need to touch it when it is fresh and smell it. Also, there is a big difference between the smell of exhaust fumes and the smell of raw gasoline. Either way, it is a serious deal, and merely begs the question of which way you prefer to die; asphyxiation or burns. You should get your car on a lift and examine the fuel lines and the exhaust system.
Last edited by DSilk56; 10-02-2012 at 01:18 PM.