
378 Glossary of Terms and Abbreviations
API Gravity: A gravity scale established by the American Petroleum Institute and
in general use in the petroleum industry, the unit being called “the API
degree.” This unit is dened in terms of specic gravity (SG) as follows:
APIGravity
SG
.
.
141 5
131 5
API Guidelines for SAE Viscosity-Grade Engine Testing: Guidelines estab-
lished for different oil viscosity grades that allow certain engine and bench
test results to be used in lieu of additional testing. These guidelines are
described in detail in Annex F of the Guidelines.
API Mark: A mark licensed by API and used by oil marketers in connection with ...