Light crude oil
Light crude oil is liquid petroleum that has a low density and flows freely at room temperature. It has a low viscosity, low specific gravity and high API gravity due to the presence of a high proportion of light hydrocarbon fractions. It generally has a low wax content. Light crude oil receives a higher price than heavy crude oil on commodity markets because it produces a higher percentage of gasoline and diesel fuel when converted into products by an oil refinery.
The clear cut definition of light and heavy crude varies because the classification is based more on practical grounds than theoretical. The New York Mercantile Exchange (NYMEX) defines light crude oil for domestic U.S. oil as having an API gravity between 37° API (840 kg/m3) and 42° API (816 kg/m3), while it defines light crude oil for non-U.S. oil as being between 32° API (865 kg/m3) and 42° API (816 kg/m3). The National Energy Board of Canada defines light crude oil as having a density less than 875.7 kg/m3 (API gravity greater than 30.1° API). The government of Alberta, which produces most of the oil in Canada, disagrees and defines it as oil with a density less than 850 kg/m3 (API gravity greater than 35° API) The Mexican state oil company, Pemex, defines light crude oil as being between 27° API (893 kg/m3) and 38° API (835 kg/m3). This variation in definition occurred because countries such as Canada and Mexico tend to have heavier crude oils than are commonly found in the United States, whose large oil fields historically produced lighter oils than are found in many other countries. Canada also uses the SI of units to measure oil rather than American oil industry conventional units, and the base temperature for density calculations is different in Canada at 15 °C (59 °F) than the US at 60 °F (15.56 °C), resulting in slightly different density values.
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