By law, auto manufacturers cannot endorse a particular brand of motor oil. Many have gone on record, however, to state that using re-refined oil does not affect warranty coverage. As long as an oil is API certified, it doesn’t matter if the oil is re-refined, mineral-oil-based, synthetic, partly synthetic, or hydrocracked. Here are a few positions:
“Ford recommends using engine oil meeting Ford Specification ESE-M2C153-E and licensed as certified for gasoline engines by the American Petroleum Institute (API). Re-refined oils are capable of meeting these requirements… it is the responsibility of the oil marketers to ensure that their products meet the requirements consistently and continuously. It is Ford’s view that a re-refined oil produced with stringent manufacturing controls, batch-to-batch testing of low-temperature viscosity performance and other significant characteristics, would comply with Ford’s recommendations.”
“G.M recommends for use in its vehicles oils that meet performance requirements specified in the latest Performance Standard and Approval Committee Minimum Performance Standard, and that are certified by the American Petroleum Institute… oils meeting those requirements can be made with either virgin or re-refined base oils… General Motors encourages the use of properly qualified re-refined products which consistently satisfy recommended performance requirements.
“Detroit Diesel.favors the recycling of waste oil and permits the use of re-refined oils in all engine product lines, provided the re-refined oil meets the SAE Viscosity, API, and Military specifications.”