Which description best defines API gravity in the context of fuels?

Which description best defines API gravity in the context of fuels?

• A. Weight Of Fuel Relative To Water
• B. Vapor Pressure Relative To Water
• C. Boiling Point Relative To Water
• D. Color Relative To Water

Answer: (A)

API gravity describes the density of a petroleum liquid relative to water, typically measured at 60 °F. It’s derived from the liquid’s specific gravity to water and shown as API degrees; higher API gravity means the liquid is lighter than water, while lower API gravity means it’s heavier. This density-relative measure helps classify fuels and crude oils (light hydrocarbons have higher API gravity, heavy crudes have lower). The other options describe volatility (vapor pressure), boiling behavior (boiling point), or appearance (color), none of which define API gravity.

API gravity describes the density of a petroleum liquid relative to water, typically measured at 60 °F. It’s derived from the liquid’s specific gravity to water and shown as API degrees; higher API gravity means the liquid is lighter than water, while lower API gravity means it’s heavier. This density-relative measure helps classify fuels and crude oils (light hydrocarbons have higher API gravity, heavy crudes have lower). The other options describe volatility (vapor pressure), boiling behavior (boiling point), or appearance (color), none of which define API gravity.