The latest heavy-duty engine oil categories of American Petroleum Institute. The primary oil and natural gas trade association in the United States. API operates a voluntary licensing and certification program that allows engine oil marketers to use the API Engine Oil Quality Marks if their products meet specific requirements. CK-4 and FA-4 saw first license December 1, 2016.
Previously referred to as Proposed Category 11 (PC-11), and driven by increasingly strict regulatory measures worldwide, this API upgrade focuses on drastically reducing greenhouse gas Mobile sources - Pollutant exhaust gases created by the combustion of fuel. Water and CO2 are not included in this category, but CO, NOx, and hydrocarbons are and are thus subject to legislative control. All three are emitted by gasoline engines, while diesel engines also emit particulates that are regulated. Stationary sources - The release of sulfur oxides and particulates from power stations that can be influenced by fuel composition. Local authorities control the sulfur content of heavy fuel oils used in such applications. and improving fuel economy, and emphasizes improvements in A reaction occurring when oxygen attacks petroleum fluids. Oxidation is accelerated by heat, light, metal catalysts, and the presence of water, acids, or solid contaminants. Oxidation leads to increased viscosity and deposit formation. stability, shear stability and resistance to aeration. For the first time in history, in response to the range of A measure of a fluid's resistance to flow. A fluid with a higher viscosity flows less easily. grades in the market, this category upgrade has been split into two. API FA-4 (previously referred to as PC-11B) oils meets developing market needs and API CK-4 (PC-11A) offers backward compatibility in higher High Temperature High Shear. A measure of a fluid’s resistance to flow under conditions resembling highly-loaded journal bearings in fired internal combustion engines, typically 1 million s–1 at 150°C. viscosity grades.
- First License date 1st December 2016
- These new oils are simply better than today’s API CJ-4 oils
- Predominantly affects large diesel engines, off-highway vehicles including construction and agricultural equipment
- First time the category has been split. Due to the split, differentiated by their HTHS limit, awareness on using/specifying the correct oil becomes even more critical:
API CK-4 : Backward compatible – minimum 3.5 cP HTHS
API FA-4 : For modern engine designs – 2.9-3.2 cP HTHS