Dry gas is an alcohol-based additive gas used in automobiles to prevent water from freezing in water-contaminated fuels, thereby restoring the combustive power of gasoline spoiled by water.
Dry gas is added to the fuel tank and binds to the water to burn it off, and typically contains either methanol or isopropyl alcohol.
[2] Current gasoline-powered automobiles can safely run with up to a 10% ethanol solution without requiring any modification.
However, when the ethanol content reaches 15% or higher, older vehicles need to replace their fuel lines to prevent degradation and rupture.
[2] In this case, the electric fuel pump may also need modification to prevent ethanol "dry rot.