Is It Ok to Use Old Gas

While old gasoline won’t hurt an engine, it’ll just make it run inefficiently or fail to fire at all. You can certainly dispose of old gas, but you can also reuse it by diluting it with fresh gas (see Step 2). However, if the leftover gasoline shows particles of rust, dirt, or discoloration, it may be contaminated.

How long before gas goes bad?

Regular gasoline has a shelf life of three to six months, while diesel can last up to a year before it begins to degrade. On the other hand, organic-based Ethanol can lose its combustibility in just one to three months due to oxidation and evaporation. Tracking the age of the fuel in your tank can be a challenge.

How can you tell if gasoline is bad?

If it has a rough idle, stalls frequently during acceleration, or fails to start at all, your gas has gone bad. Sometimes, bad gasoline will also cause the check engine light to illuminate. You can also tell if gasoline is bad by its appearance. If it’s darker than usual or has a sour smell, it’s probably bad.