[Code of Federal Regulations] [Title 40, Volume 30] [Revised as of July 1, 2004] From the U.S. Government Printing Office via GPO Access [CITE: 40CFR1065.201] [Page 659] TITLE 40--PROTECTION OF ENVIRONMENT CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PART 1065_TEST PROCEDURES AND EQUIPMENT--Table of Contents Subpart C_Test Fuels and Analytical Gases Sec. 1065.201 General requirements for test fuels. (a) For all emission tests, use test fuels meeting the specifications in this subpart, unless the standard-setting part directs otherwise. For any service accumulation on a test engine, if we do not specify a fuel, use the specified test fuel or a fuel typical of what you would expect the engine to use in service. (b) We may require you to test the engine with each type of fuel it can use (for example, gasoline and natural gas). (c) If you will produce engines that can run on a type of fuel (or mixture of fuels) that we do not specify in this subpart, we will allow you to test with fuel representing commercially available fuels of that type. However, we must approve your fuel's specifications before you may use it for emission testing. (d) You may use a test fuel other than those we specify in this subpart if you do all of the following: (1) Show that it is commercially available. (2) Show that your engines will use only the designated fuel in service. (3) Show that operating the engines on the fuel we specify would increase emissions or decrease durability. (4) Get our written approval before you start testing. (e) We may allow you to use other test fuels (for example, California Phase 2 gasoline) if they do not affect the demonstration of compliance.