Is gasoline blended for winter use more volatile than gasoline blended for summer use?

Gasoline blended for winter use is indeed more volatile than gasoline blended for summer use. This is primarily due to the need for improved engine starting and operation in colder temperatures. Higher volatility in winter blends means that the gasoline vaporizes more easily at lower temperatures, which facilitates better combustion when the engine is cold.

In contrast, summer blends of gasoline are formulated to be less volatile to prevent vapor lock and evaporation losses during hotter weather. Excessively volatile fuel in warm temperatures could lead to challenges with engine performance and fuel system reliability, as it can evaporate too quickly.

The differences in volatility between winter and summer blends are part of a regulatory effort to ensure that vehicles operate efficiently under varying environmental conditions throughout the year.