Trading concepts
API gravity
A measure of crude oil density relative to water — higher API = lighter crude.
API gravity is the American Petroleum Institute's measure of crude oil density relative to water. Higher API = lighter crude = more valuable (more gasoline and middle distillate yield).
- Heavy: <22° API (e.g., Western Canadian Select ~20° API)
- Medium: 22-31° API (e.g., Arab Heavy ~28° API)
- Light: >31° API (e.g., WTI ~40° API, Brent ~38° API)
Sulphur content (sweet <0.5%, sour >0.5%) is the other critical quality dimension.
See also