ASTM D5188-16

5.1 The tendency of a fuel to vaporize in automotive engine fuel systems is indicated by the vapor-liquid ratio of the fuel.

5.2 Automotive fuel specifications generally include T _{(V/L = 20)} limits to ensure products of suitable volatility performance. For high ambient temperatures, a fuel with a high value of T_{(V/L = 20)}, indicating a fuel with a low tendency to vaporize, is generally specified; conversely for low ambient temperatures, a fuel with a low value of 1.1 This test method covers the determination of the temperature at which the vapor formed from a selected volume of volatile petroleum product saturated with air at 0 °C to 1 °C (32 °F to 34 °F) produces a pressure of 101.3 kPa (one atmosphere) against vacuum. This test method is applicable to samples for which the determined temperature is between 36 °C and 80 °C (97 °F and 176 °F) and the vapor-liquid ratio is between 8 to 1 and 75 to 1.

1.2 This test method is applicable to both gasoline and gasoline-oxygenate blends.

1.3 The values stated in SI units are to be regarded as standard.

1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For specific warnings, see Section 7 and subsection 8.1.1.