Engine oil viscosity classification

Table 1. Engine Oil Viscosity Classification SAE J300 (April 1997)a...

J300 Engine Oil Viscosity Classification, revised May 2004 (Warrendale, PA Society of Automotive Engineers). 

The viscosity of automotive engine oil is the main controlling property for manufacture and for selection to meet the particular service condition using the American Society of Automotive Engineers (SAE) viscosity classification. The higher-viscosity oils are standardized at 210°F (99°C), and the lighter oils that are intended for use in cold weather conditions are standardized at 0°F (-18°C). 

The classification of motor oils has not been completed in the ISO standard because the technical differences between motors in different parts of the world, particularly Europe and the United States, make the implementation of a single system of classification and specifications very difficult. In practice, different systems coming from national or international organizations are used. The best known is the SAE viscosity classification from the Society of Automotive Engineers, developed in the United States. 

SAE (Society of Automotive Engineers)—organization responsible for the establishment of many U.S. automotive and aviation standards, including the viscosity classifications of engine oils and gear oils. See SAE viscosity grades. 

SAE viscosity grades-engine oil classification system developed by the Society of Automotive Engineers (SAE), based on the measured viscosity of the oil at either -18°C (-0.4°F), using test method... 

In a fully synthetic oil, there is almost certainly some mineral oil present. The chemical components used to manufacture the additive package and the viscosity index improver (VI) contain mineral oil. When all these aspects are considered, it is possible for a "fully synthetic" engine oil to surpass mineral oil (Shubkin, 1993). Synthetic oils fall into general ASTM classification (a) synthetic hydrocarbons (poly-a-olefins, alkylated aromatics, cycloaliphatics) (b) organic esters (dibasic acid esters, polyol esters, polyesters) (c) other fluids (polyalkylene glycols, phosphate esters, silicates, silicones, polyphenyl esters, fluorocarbons). 

Lubricant requirements and specifications. The development of North American classification systems for the SAE began in 1911 on the basis of viscosity alone. In 1947, the API (American Petroleum Institute) developed a performance classification system for engine oils in terms of regular, premium and heavy duty lubricants. By 1952, the API and ASTM (American Society for Testing and Materials) further advanced the system to generally classify engine oils. In 1970, the TRIPARTITE of API, ASTM, and SAE was established to manage a completely new API classification system, see Fig. 2.12 (Haycock, 1993). 

Oil viscosity index classification Using Table 1 (Appendix) and Chapter 2.5 as references, write viscosity index values for winter and summer engine oils. 

Viscosity classification In the description of SAE grade oils, such as SAE 5 W, does the W designate a viscosity that applies to warm or winter temperatures Which multigrade engine oil designation is incorrect SAE 5W-20, SAE 10W-50, or SAE 5W-10W-30 ... 

A new proposed SAE Viscosity Classification not only reflects lower than 0°F temperature cranking characteristics of an oil, but also covers low temperature pumpability characteristics (j), 10). Low temperature cranking success without oil pump-ability could result in oil starvation and subsequent engine damage. This new proposed classification attempts to establish a maximum cranking viscosity and then classifies oils according to what temperature they match this viscosity. It also includes a low shear test (mini-rotor viscometer) to duplicate pumpability of the oil at various low temperatures. Needless to say, minimum... 

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