American Petroleum Institute (API) gravity is a key parameter for classifying crude oil and petroleum products by density. This study presents the development of tables of oil gravities ranging from 0.600 to 1.025, from which the American Petroleum Institute (API) gravity can be derived without resorting to the equation of state. This research also examined four densities across four oil products (gasoline, kerosene, gas oil, and lubricating oils), yielding a total of 16 models. Moreover, the results of the laboratory test showed that the gravity of the oils is close, take for instance (the gravity of gasoline ranges between 0.700 to 0.750, the density of kerosene ranges from 0.750 to 0.800, while the density of gas oil ranges from 0.800 to 0.850, and lastly the range of gravity of lubricating oils ranged from 0.850 to 0.900). In conclusion, the tables produced by this study will enable direct measurement of API gravity, saving testers time, improving accuracy, and reducing errors.
Mahmod A. Abdulqader (2026) studied this question.