API donut
English edit
Etymology edit
API + donut; from American Petroleum Institute, and its shape.
Noun edit
API donut (plural API donuts)
- (US, automotive) An information table found on cans of motor oil, conforming to U.S. standards, which indicates the weight (viscosity) and type of oil. The central circle provides the oil viscosity rating (ie. 10W50), while the upper annulus section provides the oil type (ie. SP).