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. Service Category SN was first introduced in 2010 for use in gasoline engines. Oils meeting API SN are designed to provide improved performance across a wide range of areas including high temperature deposit protection for pistons and improved protection against the formation of engine A thick, dark residue, normally of mayonnaise consistency, that accumulates on nonmoving engine interior surfaces. Generally removable by wiping unless baked to a carbonaceous consistency, its formation is associated with insolubles overloading of the lubricant..
Oils that satisfy API Service Category SN are superior in performance to those meeting API SM and earlier and can effectively lubricate engines calling for those Service Categories.
API SN is typically seen claimed in conjunction with a wide range of different performance claims including International Lubricants Standardization and Approval Committee. A collaboration between the American Automobile Manufacturers Association (AAMA), Chrysler, Ford, GM, and the Japanese Automotive Standards Organization. ILSAC GF- engine oil specifications target fuel economy, emission system protection, and enhanced engine oil robustness. standards, European Automobile Manufacturers Association (Association des Constructeurs Européens d'Automobiles). The primary automotive standards organization in the European Union, ACEA defines performance specifications for automotive lubricants. Oil Sequences and many OEM performance specifications.
In some cases oils meeting API SN also carry a Resource Conserving claim to show that the oil has been formulated to improve fuel efficiency. These oils are typically low 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. (≤ 3.5cP) SAE 5W-30, 5W-20, 0W-30 and 0W-20 based on API Group II, Group III or Group IV base oils and coupled with ILSAC GF-5.
For more information on API SN, contact your Lubrizol representative.