StacksVerified U.S. regulatory reference

40 CFR §1036.620

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
For model years 2014 through 2016, you may certify your compression-ignition engines to alternate fuel consumption standards as described in this section. However, you may not certify engines to these alternate standards if they are part of an averaging set in which you carry a balance of banked credits. For purposes of this section, you are deemed to carry credits in an averaging set if you carry credits from advanced technology that are allowed to be used in that averaging set.
  1. (a)The standards of this section are determined from the measured emission rate of the engine of the applicable baseline 2011 engine family or families as described in paragraphs (b) and (c) of this section. Calculate the CO2 emission rate of the baseline engine using the same equations used for showing compliance with the otherwise applicable fuel consumption standard. The alternate emission rate for light and medium heavy-duty vocational-certified engines (using the transient cycle) is equal to the baseline emission rate multiplied by 0.975. The alternate emission rate for tractor-certified engines (using the SET duty cycle) and all other Heavy HDE is equal to the baseline emission rate multiplied by 0.970. The in-use FEL for these engines is equal to the alternate standard multiplied by 1.03.
  2. (b)This paragraph (b) applies if you do not certify all your engine families in the averaging set to the alternate standards of this section. Identify separate baseline engine families for each engine family that you are certifying to the alternate standards of this section. For an engine family to be considered the baseline engine family, it must meet the following criteria:
    1. (1)It must have been certified to all applicable emission standards in model year 2011. If the baseline engine was certified to a NOX FEL above the standard and incorporated the same emission control technologies as the new engine family, you may adjust the baseline CO2 emission rate to be equivalent to an engine meeting the 0.20 g/hp·hr NOX standard (or your higher FEL as specified in this paragraph (b)(1)), using certification results from model years 2009 through 2011, consistent with good engineering judgment.
      1. (i)Use the following equation to relate model year 2009-2011 NOX and CO2 emission rates (g/hp·hr): CO2 = a × log(NOX)+b.
      2. (ii)For model year 2014-2016 engines certified to NOX FELs above 0.20 g/hp·hr, correct the baseline CO2 emissions to the actual NOX FELs of the 2014-2016 engines.
      3. (iii)Calculate separate adjustments for emissions over the SET duty cycle and the transient cycle.
    2. (2)The baseline configuration tested for certification must have the same engine displacement as the engines in the engine family being certified to the alternate standards, and its rated power must be within five percent of the highest rated power in the engine family being certified to the alternate standards.
    3. (3)The model year 2011 U.S.-directed production volume of the configuration tested must be at least one percent of the total 2011 U.S.-directed production volume for the engine family.
    4. (4)The tested configuration must have cycle-weighted BSFC equivalent to or better than all other configurations in the engine family.
  3. (c)This paragraph (c) applies if you certify all your engine families in the primary intended service class to the alternate standards of this section. For purposes of this section, you may combine Light HDE and Medium HDE into a single averaging set. Determine your baseline CO2 emission rate as the production-weighted emission rate of the certified engine families you produced in the 2011 model year. If you produce engines for both tractors and vocational vehicles, treat them as separate averaging sets. Adjust the CO2 emission rates to be equivalent to an engine meeting the average NOX FEL of new engines (assuming engines certified to the 0.20 g/hp·hr NOX standard have a NOX FEL equal to 0.20 g/hp·hr), as described in paragraph (b)(1) of this section.
  4. (d)-(e) [Reserved]
  5. (f)You need our approval before you may certify engines under this section, especially with respect to the numerical value of the alternate standards. We will not approve your request if we determine that you manipulated your engine families or engine configurations to certify to less stringent standards, or that you otherwise have not acted in good faith. You must keep and provide to us any information we need to determine that your engine families meet the requirements of this section. Keep these records for at least five years after you stop producing engines certified under this section.