CFR > Title 40 - Protection of Environment > CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY > SUBCHAPTER C—AIR PROGRAMS (Parts 50–99) > PART 86—CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES > SUBPART D—Emission Regulations for New Gasoline-Fueled and Diesel-Fueled Heavy-Duty Engines; Gaseous Exhaust Test Procedures (§86.301-79 to §86.348-79) > 86.347-79—Alternative calculations for diesel engines.

86.347-79—Alternative calculations for diesel engines.

(a) This section applies to Diesel engines only. Gasoline-fueled engines must use the calculations in § 86.345.
(b) For Diesel engines, the calculations specified in 40 CFR 86.977-15 may be substituted for § 86.345.
(c) The modal BSFC and weighted BSFC shall be calculated per § 86.345.
(d) If the provisions of this section are used, a CO2 measurement is not required.
(e) Both 40 CFR 86.977-15(a) and § 86.313 shall apply to air-flow measurements. For the purposes of this section, the air-flow measurement accuracy specified in § 86.313 shall be ±1 percent.