Section 86.1841-01 - Compliance with emission standards for the purpose of certification(a) Certification levels of a test vehicle will be calculated for each emission constituent applicable to the test group for both full and intermediate useful life as appropriate.(1) If the durability demonstration procedure used by the manufacturer under the provisions of § 86.1823, § 86.1824, or § 86.1825 requires a DF to be calculated, the DF shall be applied to the official test results determined in § 86.1835-01(c) for each regulated emission constituent and for full and intermediate useful life, as appropriate, using the following procedures: (i) For additive DF's, the DF will be added to the emission result. The sum will be rounded to the same level of precision as the standard for the constituent at full and/or intermediate useful life, as appropriate. This rounded sum is the certification level for that emission constituent and for that useful life mileage.(ii) For multiplicative DFs, the DF will be multiplied by the emission result for each regulated constituent. The product will be rounded to the same level of precision as the standard for the constituent at full and intermediate useful life, as appropriate. This rounded product is the certification level for that emission constituent and for that useful life mileage.(iii) For a composite standard of NMHC+NOX, the measured results of NMHC and NOX must each be adjusted by their corresponding deterioration factors before the composite NMHC+NOX certification level is calculated. Where the applicable FTP exhaust hydrocarbon emission standard is an NMOG standard, the applicable NMOG deterioration factor must be used in place of the NMHC deterioration factor, unless otherwise approved by the Administrator.(2) If the durability demonstration procedure used by the manufacturer under the provisions of § 86.1823, § 86.1824, or § 86.1825, as applicable, requires testing of the EDV with aged emission components, the official results of that testing determined under the provisions of § 86.1835-01(c) shall be rounded to the same level of precision as the standard for each regulated constituent at full and intermediate useful life, as appropriate. This rounded emission value is the certification level for that emission constituent at that useful life mileage.(3) Compliance with full useful life CO2 exhaust emission standards shall be demonstrated at certification by the certification levels on the duty cycles specified for carbon-related exhaust emissions according to § 600.113 of this chapter.(4) The rounding required in paragraph (a) of this section shall be conducted in accordance with the provisions of § 86.1837-01 .(b) To be considered in compliance with the standards for the purposes of certification, the certification levels for the test vehicle calculated in paragraph (a) of this section shall be less than or equal to the standards for all emission constituents to which the test group is subject, at both full and intermediate useful life as appropriate for that test group.(c) Every test vehicle of a test group must comply with all applicable exhaust emission standards before that test group may be certified.(d) Every test vehicle of an evaporative/refueling family must comply with all applicable evaporative and/or refueling emission standards before that family may be certified.(e) Unless otherwise approved by the Administrator, manufacturers must not use Reactivity Adjustment Factors (RAFs) in their calculation of the certification level of any pollutant for any vehicle.64 FR 23925, May 4, 1999, as amended at 65 FR 6864 , Feb. 10, 2000; 66 FR 19310 , Apr. 13, 2001; 71 FR 2836 , Jan. 17, 2006; 75 FR 25690 , May 7, 2010; 76 FR 39522 , July 6, 2011