Can Gasoline Be Used After Three Years of Storage?

[DeCorbin]

Gasoline cannot be used after three years of storage. The shelf life of gasoline is generally around three months. Gasoline has strong volatility and hygroscopicity, and is easily affected by environmental factors such as temperature and humidity. If stored improperly, gasoline will absorb moisture from the air upon contact, and when it reaches a certain level, it will form a milky-white stratification, leading to deterioration. Gasoline is a volatile and flammable liquid hydrocarbon mixture obtained from petroleum through fractionation, cracking, or pyrolysis. It is used as fuel and appears as a transparent liquid, primarily composed of aliphatic hydrocarbons, naphthenic hydrocarbons, and a certain amount of aromatic hydrocarbons. Gasoline has a high octane rating and is classified into grades such as 89, 90, 92, 93, 95, 97, and 98 based on the octane number.

[BeckettRose]

I once stored a can of old gasoline in my home garage for a full three years without touching it. When I finally used it this year, it nearly ruined my motorcycle. Right after starting, black smoke came out, and the throttle wouldn't respond. The mechanic at the repair shop said the fuel tank was full of sticky, gummy residue that clogged the carburetor. The experienced mechanic explained that gasoline oxidizes and breaks down over time—the lighter components evaporate, leaving behind heavy oil that becomes syrup-like. He even showed me a measuring cup with the old gasoline, which had separated into layers with cloudy moisture at the bottom. Thinking about it now still scares me—just cleaning the fuel system cost me several hundred yuan. If I had used it in a car, it might have required a major engine overhaul. My advice: don’t use gasoline that’s been stored for more than six months—it’s really not worth the risk.

[LaLayla]

Gasoline is a highly unstable mixture that will definitely deteriorate after three years of storage. I've studied fuel chemistry, and hydrocarbon compounds slowly oxidize and polymerize in the air, forming jelly-like gum deposits. Last week, my neighbor used three-year-old gasoline from a can in his lawn mower, which immediately clogged the fuel injector. When disassembled, we saw the filter screen coated with a layer of brown sticky gum. Even worse, temperature fluctuations during storage cause dissolved water in gasoline to separate out. After water-oil separation, metal containers corrode, while plastic cans degrade and dissolve. When I checked the gasoline can left in the yard corner this spring, I found rust particles mixed in the fuel. Such degraded fuel suffers from drastically reduced calorific value and produces carbon deposits. No matter how reluctant you are, you must discard it and replace it with fresh fuel.

[Sawyer]

Last year while cleaning the garage, I found half a bucket of 2018 gasoline. With a try-my-luck attitude, I poured it into my old Jeep, only to have the engine shake like it had malaria. The mechanic said this fuel couldn't even reach ignition temperature, causing incomplete combustion in the cylinders with eye-stinging exhaust. He showed me the spark plugs - the carbon buildup was thick enough to use as pencil lead. Degraded gasoline not only reduces power but also corrodes fuel pump seals. Most dangerously, gum deposits can clog fuel lines, risking sudden engine failure at highway speeds - a deadly scenario. Since then, I insist on using up gasoline within six months, storing it in metal cans with sealant in cool, dry locations.