REID VAPOR PRESSURE

A measure of volatility of a fuel, its ability to vaporize. Reid vapor pressure, the specific designation, is named after the man who designed the test apparatus for measuring vapor pressure (q.v.).

Refers to the vapor pressure of the fuel expressed in the nearest hundredth of a pound per square inch (psi) with a higher number reflecting more gasoline evaporation. (See also Gasoline Volatility.)