API approves new diesel engine oil standards
2 March 2016
The American Petroleum Institute (API) announced that it has approved two new diesel engine oil standards, API Service Categories CK-4 and FA-4. During the development process, the new categories were known as PC-11 (proposed category 11).
The new service categories improve upon existing standards by providing enhanced protection against oil oxidation and protection against engine wear, particulate filter blocking, piston deposits, and degradation of low- and high-temperature properties.
API category CK-4 (called PC-11A during development) of higher HTHS viscosity (3.5 cP) is backwards compatible with current engines designed for oils category CJ-4. Category FA-4 (PC-11B) of lower HTHS viscosity of 2.9-3.2 cP—intended to reduce engine friction and provide fuel economy improvements—is not backward compatible with CJ-4.
API is now preparing to license engine oils against the new standards:
- API CK-4 and FA-4 will first appear in the API Service Symbol “Donut” on December 1, 2016. This delay in licensing allows marketers time to test their new formulations and ready them for market.
- Most truck manufacturers recommending API-licensed CJ-4 engine oils will likely recommend truck owners start using CK-4 oils as soon as they are available. API CK-4 oils will better protect today’s diesel engines, said the API.
- The FA-4 standard describes lower viscosity oils specifically formulated for use in select high-speed four-stroke cycle diesel engines designed to meet 2017 model year on-highway GHG emission standards. Some engine manufacturers might recommend FA-4 oils for their previous model-year vehicles, but it is more likely that manufacturers will recommend the oils starting with the 2017 model year engines.
The new categories have been developed through collaborative effort between API’s Lubricants Group, the Truck & Engine Manufacturers Association (EMA) and the American Chemistry Council (ACC).
Source: API