Industry organizations and vehicle manufacturers establish sets of performance requirements lubricants must meet in order to be used safely in that industry or manufacturer’s equipment. To meet the American Petroleum Institute’s API SN specification, for example, a motor oil must meet minimum performance requirements in a range of tests that measure viscosity increase, deposits, engine wear and other important areas. When you pick up a quart of oil and read on the back label that the oil is recommended for API SN, you know the oil is safe to use in your vehicle that requires API SN-quality oil and should provide reliable performance and protection. Lubricant specifications act as safeguards that protect motorists from the negative effects of low-quality lubricants and take the guess work out of selecting the correct lubricant.
Minimum Performance Requirements
Two lubricants recommended for the same specification (API SN, for example) do not necessarily provide equal performance and protection, however. Lubricants meeting the specification requirements have only met the minimum performance requirements, leaving room for significant differences in performance. For example, API SN and ILSAC GF-5 require weight lost due to volatility to be no greater than 15 percent. While some oils may barely meet the requirement, AMSOIL Signature Series 5W-30 Synthetic Motor Oil (ASL), for example, demonstrates only 6.9 percent weight loss due to volatility, offering better performance. Those who demand the highest possible performance should dig deeper into each lubricant’s typical technical properties to find the one that offers the best performance.
European automakers often have their own specifications, such as Volkswagen’s VW 502.00/505.00 or BMW’s BMW LL-04. American manufacturers are following suit, with General Motors introducing its proprietary dexos specification in 2011. OEM specifications tend to be more stringent than industry specs.