Vehicles required to meet the emission standards of this part must meet the following additional requirements, except as noted elsewhere in this part:
(a) Adjustable parameters. Vehicles that have adjustable parameters must meet all the requirements of this part for any adjustment in the physically adjustable range. We may require that you set adjustable parameters to any specification within the adjustable range during any testing. See 40 CFR part 86 for information related to determining whether or not an operating parameter is considered adjustable. You must ensure safe vehicle operation throughout the physically adjustable range of each adjustable parameter, including consideration of production tolerances. Note that adjustable roof fairings are deemed not to be adjustable parameters.
(b) Prohibited controls. You may not design your vehicles with emission control devices, systems, or elements of design that cause or contribute to an unreasonable risk to public health, welfare, or safety while operating. For example, this would apply if the vehicle emits a noxious or toxic substance it would otherwise not emit that contributes to such an unreasonable risk.
(c) Air conditioning leakage. Loss of refrigerant from your air conditioning systems may not exceed 1.50 percent per year, except as allowed by paragraph (c)(3) of this section. Calculate the total leakage rate in g/year as specified in 40 CFR 86.1867-12(a). Calculate the percent leakage rate as: [total leakage rate (g/yr)] / [total refrigerant capacity (g)] x 100. Round your leakage rate to the nearest one-hundredth of a percent. See Sec. 1037.150 for vocational vehicles.
(1) For purpose of this requirement, ``refrigerant capacity'' is the total mass of refrigerant recommended by the vehicle manufacturer as representing a full charge. Where full charge is specified as a pressure, use good engineering judgment to convert the pressure and system volume to a mass.
(2) [Reserved]
(3) If your total refrigerant capacity is less than 734 grams, your leakage rate may exceed 1.50 percent, as long as the total leakage rate does not exceed 11.0 g/yr. If your system uses a refrigerant other than HFC-134a, you may adjust your leakage rate as specified in paragraph (c)(2) of this section. [76 FR 57398, Sept. 15, 2011, as amended at 78 FR 36392, June 17, 2013]