Diesel Base Fuels. The standard diesel test fuel for highway engines should meet the EPA specifications outlined in 40 CFR Part 86.1313-98 with the exception of the sulfur content, which the applicant should specify. For nonroad engines, the test fuel should be that described in 40 CFR Part 89.330 or another fuel as specified by the control technology applicant. For stationary source engines, the permitting authority may dictate fuel requirements. Therefore, applicants may wish to use test fuel other than the 40 CFR Part 89.330 test fuel. If this is the case, manufacturers will provide the specifications of the test fuel chosen. Because the performance and durability of many types of diesel retrofit technologies are affected by the sulfur content of the diesel fuel, applicants should specify the maximum sulfur level of the fuel for which their technologies are designed. The sulfur content of the ETV test fuel should be no less than 66 percent of the stated maximum sulfur content. (Because refinery and blending operations are such that very low sulfur content control is difficult, test fuel with a sulfur content of 15 ppm or below is not constrained by the “66 percent rule”. The actual sulfur content of the test fuel batch is to be reported.) Other test fuels should meet the applicable EPA specifications outlined in 40CFR Part 86.1313. It is permissable for testing organizations to add sulfur to the fuel if doing so is necessary to achieve the required fuel sulfur content for either baseline or controlled engine tests. During ETV testing, baseline engines should be fueled with the standard fuels that are representative of nominal in-use fuels and controlled engines with low sulfur versions of the standard fuels that are representative of the applicant’s recommended or required fuel.
