For most of us, gasoline never seems to sit around for very long. But when you do store gas or go a long time without using it, the question arises: does gas go bad? Let’s take a closer look at the shelf life of gasoline and what can happen when you store it for too long.
The answer is yes. How long does gas last? That depends on a variety of factors, such as what type of fuel it is and how and where it is stored. Heat, oxygen and humidity all have an impact on the condition of stored fuel.
In general, pure gas begins to degrade and lose its combustibility as a result of oxidation and evaporation in three to six months, if stored in a sealed and labeled metal or plastic container. Ethanol-gasoline blends have a shorter shelf life of two to three months. Fuel stabilized gasoline can last between one and three years under optimal conditions. Gas stored in a car tank begins to degrade in just about a month.
Old gas does not become contaminated necessarily, but rather loses its combustible properties and volatile compounds. When you use gasoline that’s too old, it can damage internal engine components. It may also start to form a gum residue that could cause blockages. If there’s ethanol in the fuel, it may draw water vapor into your fuel line, which could result in internal corrosion.