Standard Diesel Test Fuel. 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. For nonroad engines, the test fuel Table 3. Minimum durability testing periods (CARB, 2001) Engine Type Engine Size Minimum Durability Testing Period Highway Light heavy-duty, generally 70 to 170 hp, GVWRa normally less than 19,500 lb. 5 yr or 60,000 miles (or equivalent time in hours) Medium heavy-duty, generally 170 to 250 hp, GVWRa normally from 19,500 to 33,000 lb. 5 yr or 100,000 miles (or equivalent time in hours) Heavy heavy-duty, generally exceeds 250 hp, GVWRa normally exceeds 33,000 lb. 5 yr or 150,000 miles (or equivalent time in hours) Nonroad and Under 25 hp and for constant speed engines rated under 50 hp with rated speeds greater than or equal to 3,000 rpm 3 yr 1,600 hr operation Stationary At or above 25 hp and under 50 hp 4 yr 2,600 hr operation At or above 50 hp 5 yr 4,200 hr operation aGVWR = Gross Vehicle Weight Rating should be that described in 40 CFR Part 89.330 or another fuel as specified by the control technology applicant. 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% 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 to the “66% 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. Adding sulfur to the fuel by the test laboratories is permissible if necessary to achieve the required fuel sulfur content for either baseline or controlled engine tests. During ETVs, 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.
