Although variously defined, the upper limit for heavy oil is 22° API gravity with a viscosity of 100 cp (centipoise). The American Petroleum Institute's "API gravity" is a standard to express the ...

The American Petroleum Institute (API) estimated that crude oil inventories in the United ... At 4:52 pm ET, Brent crude was trading down $0.38 (-0.48%) on the day at $78.91.