This SAE Recommended Practice presents recommendations for test fluids that can be used to simulate real world fuels. The use of standardized test fluids is required in order to limit the variability found in commercial fuels and fluids. Commercial fuels can vary substantially between manufacturers, batches, seasons, and geographic location. Further, standardized test fluids are universally available and will promote consistent test results for materials testing. Therefore, this document: a. Explains commercial automotive fuel components; b. Defines standardized components of materials test fluids; c. Defines a nomenclature for test fluids; d. Describes preparations for test fluids; and e. Recommends fluids for testing fuel system materials. The test fluid compositions specified in Section 7 of this document are recommended solely for evaluating materials. They are not intended for other activities, such as engine development, design verification, or process validation unless agreed upon by the contracting parties. The marketplace test fuels listed in Appendix B of this document can be used for engine, vehicle, or component testing.