§ 86.1864-10 How to comply with cold temperature fleet average standards.
(a) Applicability. Cold temperature fleet average standards apply for NMHC or NMOG+NOX emissions as described in § 86.1811. Certification testing provisions described in this subpart apply equally for meeting cold temperature exhaust emission standards except as specified.
(b) Calculating the cold temperature fleet average standard. Manufacturers must compute separate sales-weighted cold temperature fleet average emissions at the end of the model year using actual sales and certifying test groups to FELs, as defined in § 86.1803-01. The FEL becomes the standard for each test group, and every test group can have a different FEL. The certification resolution for the FEL is 0.1 grams/mile for NMHC and 0.010 grams/mile for NMOG+NOX. Determine fleet average emissions separately for each set of vehicles subject to different fleet average emission standards. Do not include electric vehicles or fuel cell vehicles when calculating fleet average emissions. Starting with Tier 4 vehicles, determine fleet average emissions based on separate averaging sets for light-duty program vehicles and medium-duty vehicles. Convert units between mg/mile and g/mile as needed for performing calculations. Calculate the sales-weighted cold temperature fleet averages using the following equation, rounded to the nearest 0.1 grams/mile for NMHC and to the nearest 0.001 grams/mile for NMOG+NOX:
Equation 1 to Paragraph (b)
(c) Certification compliance and enforcement requirements for cold temperature fleet average standards. Each manufacturer must comply on an annual basis with fleet average standards as follows:
(1) Manufacturers must report in their annual reports to the Agency that they met the relevant fleet average standard by showing that their sales-weighted cold temperature fleet average emissions are at or below the applicable fleet average standard for each averaging set.
(2) If the sales-weighted average is above the applicable fleet average standard, manufacturers must obtain and apply sufficient credits as permitted under paragraph (d)(8) of this section. A manufacturer must show via the use of credits that they have offset any exceedance of the cold temperature fleet average standard. Manufacturers must also include their credit balances or deficits.