Fleet average NOx standards and reporting requirements for light-duty vehicles: chapter 4


4.1 What is a fleet average NOx value?

A fleet average NOx value is the calculated, average NOx emissions of a company's fleet of vehicles of a given model year, based on the actual number of vehicles of that model year.

4.2 For which fleets must fleet average NOx values be calculated?

Since fleet average NOx standards are different for the various regulated classes of vehicle for the 2004−2008 model years, for these years, a company must calculate separate fleet average NOx values for

  • its fleet of light-duty vehicles and light light-duty trucks; and
  • its fleet of heavy light-duty trucks and medium-duty passenger vehicles.

Starting with the 2009 model year, a company is required to calculate only a single fleet average NOx value for its combined fleet of light-duty vehicles, light-duty trucks and medium-duty passenger vehicles.

4.3 How is a fleet average NOx value calculated?

As outlined in section 24 of the Regulations, the fleet average NOx value is calculated in accordance with the following equation:

4.3 How is a fleet average NOx value calculated?

Where

  • A represents the NOx emission standard for each full useful life emission bin3;
  • B represents the number of vehicles in the fleet that conform to that NOx emission standard; and
  • C represents the total number of vehicles in the fleet.

The Regulations contain special provisions that account for the NOx benefits for hybrid electric vehicles, vehicles that conform to an NOx emission standard for an extended useful life of 15 years or 240 000 km (150 000 miles) and for vehicles of the 2004 and 2005 model years certified to bin 1 and bin 24 standards.

4.4 Are there provisions respecting the procedures for rounding the calculated fleet average NOx value?

Yes. As specified in subsection 24(2) of the Regulations, fleet average NOx values must be rounded to the same number of significant figures that are contained in the total number of vehicles in the fleet in the denominator of equation [1], but to at least three decimal places. For example, for a fleet having a total of 123 456 vehicles, a calculated fleet average NOxvalue of 0.21456878 grams/mile must be rounded to 0.214569 grams/mile.

Furthermore, consistent with the definition of "rounded" in section 1 of the Regulations, all rounding must be performed in accordance with the ASTM-E29-93a method of the American Society for Testing and Materials.

4.5 Does the calculation of fleet average NOx values account for the benefits of hybrid electric vehicles?

Yes. Under subsection 24(3) of the Regulations, a company may multiply the variable A in equation [1] by a contribution factor for hybrid electric vehicles, determined as per the United States' Code of Federal Regulations. The company's end-of-model-year report to the Minister must provide:

  • the values of the contribution factors;
  • evidence of approval by the U.S. Environmental Protection Agency (U.S. EPA) for each contribution factor; and
  • a demonstration that the factor is being applied in the fleet average NOx value calculations in the same manner as in the United States.

4.6 Does the calculation of fleet average NOx values account for the additional environmental benefits of vehicles certified with extended durability?

Yes. If a company's fleet includes vehicles certified with extended durability, the additional environmental benefits of these vehicles are recognized by lowering the company's fleet average NOx value. Under subsections 24(4) and 24(5) of the Regulations, a company may multiply the variable A in equation [1] by 0.85 for each test group with vehicles that conform to an NOx emission standard for an extended useful life of 15 years or 240 000 km (150 000 miles), instead of the required full useful life of 10 to 11 years or 120 000 miles. The vehicles must comply with the applicable standards at the intermediate useful life of 5 years or 50 000 miles in order to apply the factor. Any vehicle models certified under these provisions must be clearly identified in the end-of-model-year report.

4.7 Does the calculation of fleet average NOx values provide any recognition for the early introduction of bin 1 and bin 2 vehicles?

Yes. A company may use one of two available options to recognize the environmental benefits of introducing bin 1 and bin 2 vehicles in the early years of the phase-in of the regulated emission standards (i.e., for the 2004 and 2005 model years).

The first option is to multiply by 2 the number of vehicles that conform to a full useful life emission bin 1 and, by 1.5, the number of vehicles that conform to a full useful life emission bin 2 when calculating the denominator in equation [1] (i.e., the equation referenced in question 4.3). This approach results in a lower fleet average NOx value.

The second option is to multiply by 2 the number of vehicles that conform to a full useful life emission bin 1 and, by 1.5, the number of vehicles that conform to a full useful life emission bin 2 in the summation of the "total number of vehicles in the fleet" when calculating emission credits (i.e., the equation referenced in question 5.2). This approach results in a larger number of emission credits.

These provisions apply only to 2004 and 2005 model year vehicles and are set out in subsection 24(6) of the Regulations.

4.8 Are companies always required to calculate fleet average NOx values for their fleets?

No. In any given model year, a company can decide not to calculate a fleet average NOx value in respect of a fleet if all vehicles in that fleet are certified to bin standards having full useful life NOx emission standards that are equal to or lower than the applicable fleet average NOxstandard for that model year. This election is set out under the provisions of subsection 25(1) of the Regulations.

4.9 If a company elects not to calculate a fleet average NOx value under subsection 25(1) of the Regulations, how will the value be determined?

Under subsection 25(2) of the Regulations, the fleet average NOx value for the fleet of vehicles for which the election is made shall be deemed by the company to be the applicable fleet average NOx standard in that model year. A company that makes this election does not have to provide the full information required to make the fleet average calculations in its end-of-model-year report. However, the company would be required to clearly state in the report that it made the election and report its deemed fleet average NOxvalue.

4.10 If a company decides to exclude a group of vehicles from compliance with fleet average NOxstandards, does it change the company's requirements toward the calculation of the fleet average NOx value?

Yes. See question 6.4 for details.

3 See question 3.1 for details on bins.

4 See questions 4.5 to 4.7

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