N.C. Division of Pollution Prevention and Environmental Assistance
Re-refined Oil

Engine Oil Certifications

API Oil Seal

Re-refined oil meets the same standards for virgin oil as defined by the requirements of the American Petroleum Institute (API) and the International Lubricant Standardization and Approval Committee (ILSAC) standard for motor oil. The presence of the API doughnut symbol and the starburst on all re-refined motor oils sold verifies the quality of the oil. It has passed the same tests for cold-start, pumpability, rust-corrosion, engine-wear, high-temperature oil thickening, deposits, phosphorous and high-temperature viscosity that virgin oils do. Additionally, re-refined oil comes in the same multiple viscosity categories as does the virgin oil for the diesel or gasoline engine. Wear experienced by an engine using re-refined oil will be no different than one using virgin oil. Once used oil has been properly re-refined, it is very difficult to distinguish it from virgin oil. As a reflection of this similarity, retailers are not required to mark oil containers as to the content of re-refined base stock that it might contain.

API Donut Symbol

Unlike some products, oil is not “used up”, nor does it wear out. It does gather impurities during its use in an engine. By removing these impurities, re-refined oil helps extend the life of the original oil many times over. In fact, re-refining takes only one-third the energy used in obtaining the virgin oil from the crude stock. Moreover, it takes just one gallon of used oil, compared with 42 gallons of crude oil, to produce the same 2.5 quarts of lubricating oil. As such, it is an excellent way to conserve virgin, nonrenewable petroleum resources and reduce dependence on foreign oil. As a renewable resource, re-refined oil represents a more environmentally responsible choice.

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