SAE J300

Different brands and grades of bottled motor oil at a store

SAE J300 is a standard that defines the viscometric properties of mono- and multigrade engine oils, maintained by SAE International.[1] Key parameters for engine oil viscometrics are the oil's kinematic viscosity, its high temperature-high shear viscosity measured by the tapered bearing simulator, and low temperature properties measured by the cold-cranking simulator and mini-rotary viscometer. This standard is commonly used throughout the world, and standards organizations that do so include API and ILSAC,[2] and ACEA.[3]

The SAE has a separate viscosity rating system for gear, axle, and manual transmission oils, SAE J306, which should not be confused with engine oil viscosity. The higher numbers of a gear oil (e.g., 75W-140) does not mean that it has higher viscosity than an engine oil 20W-50.

  1. ^ "Engine Oil Viscosity Classification - J300_202104". SAE International. 30 April 2021. Retrieved 9 April 2024.
  2. ^ "Motor oil matters - Which oil is right for you?" (PDF). American Petroleum Institute. 2013. Retrieved 2018-03-18.
  3. ^ "ACEA European Oil Sequences" (PDF). ACEA. 2016.