WHY DOES GASOLINE GO BAD

Chemical and physical changes in gasoline can lead to poor engine performance and potential damage.

Gasoline is a blend of hydrocarbons and performance-enhancing additives. Over time, this mix can degrade due to chemical and physical changes. The main culprits? Oxidation, evaporation, contamination and polymerization

Contamination: Water and Ethanol Don't Mix Well.

Water can enter the fuel tanks through condensation. Ethanol-blended fuels are especially vulnerable because ethanol absorbs water. Above  certain concentrations, this can trigger phase separation, where a water layer forms at the bottom of the tank due to its heavier density compared to gasoline. When your engine pulls from this layer instead of pure fuel, it can misfire, stall, or experience corrosion of potentially expensive damage to fuel system componentry.

This surveyor recommends ethanol free gasoline, often called REC90.

Gasoline storage life is generally considered to be a few months. The storage life of gasoline can be extended significantly by the use of a quality additive to prevent oxidation. This additive should be added when the gasoline is fresh.

This surveyor recommends the use of a quality additive if the gasoline is not to be used within a short period of time.

A preferred practice is to minimize the age of the gasoline stored aboard, without risking running out of gasoline while underway..