California Code of Regulations › Title 13 - Motor Vehicles › Division 3 - Air Resources Board › Chapter 1 - Motor Vehicle Pollution Control Devices › Article 2 - Approval of Motor Vehicle Pollution Control Devices (New Vehicles) › Section 1956.1 - Exhaust Emission Standards and Test Procedures - 1985 Through 2006 Model-Year Heavy-Duty Urban Bus Engines and Vehicles

Current through Register 2024 Notice Reg. No. 28, July 12, 2024
(a) The exhaust emissions from new 1985 and
				  subsequent model heavy-duty diesel cycle urban bus engines and vehicles fueled
				  by methanol, natural gas, liquefied petroleum gas, and petroleum shall not
				  exceed the following, by model year:
(1)
				  1985-1986 -- 1.3 grams per brake horsepower-hour (g/bhp-hr) total hydrocarbons
				  (or Organic Material Hydrocarbon Equivalent [OMHCE] for methanol-fueled buses),
				  15.5 g/bhp-hr carbon monoxide (CO), and 5.1 g/bhp-hr oxides of nitrogen
				  (NOx).
(2) 1987- (a manufacturer
				  may certify to the 1988 emission standards one year early as an option) -- 1.3
				  g/bhp-hr total hydrocarbons (or OMHCE for methanol-fueled buses), 15.5 g/bhp-hr
				  CO, and 5.1 g/bhp-hr NOx.
(3)
				  1988-1990 -- 1.3 g/bhp-hr HC (or OMHCE for methanol-fueled buses), 15.5
				  g/bhp-hr CO, 6.0 g/bhp-hr NOx, 0.60 g/bhp-hr particulate matter (PM), and for
				  1990 only, 1.2 g/bhp-hr optional non-methane hydrocarbons (NMHC).
(4) 1991-1993 -- 1.3 g/bhp-hr HC (or OMHCE
				  for methanol-fueled buses), 1.2 g/bhp-hr optional NMHC, 15.5 g/bhp-hr CO, 5.0
				  g/bhp-hr NOx, and 0.10 g/bhp-hr PM. Emissions from methanol-fueled,
				  natural-gas-fueled and liquefied-petroleum-gas-fueled urban bus engines may be
				  included in the averaging program for petroleum-fueled engines other than urban
				  bus engines.
(5) 1994-1995 -- 1.3
				  g/bhp-hr HC (or OMHCE for methanol-fueled buses), 1.2 g/bhp-hr optional NMHC,
				  15.5 g/bhp-hr CO, 5.0 g/bhp-hr NOx (or optional 3.5 g/bhp-hr to 0.5 g/bhp-hr
				  NOx), and 0.07 g/bhp-hr PM. Emissions from methanol-fueled, natural-gas-fueled
				  and liquefied-petroleum-gas-fueled urban bus engines, may be included in the
				  averaging program for petroleum-fueled engines other than urban bus
				  engines.
(6) 1996-2003 -- 1.3
				  g/bhp-hr HC or OMHCE, 1.2 g/bhp-hr optional NMHC, 15.5 g/bhp-hr CO, 4.0
				  g/bhp-hr NOx, and 0.05 g/bhp-hr PM (0.07 PM g/bhp-hr in-use), except as
				  provided in paragraph (7) below.
(A) For 1996
				  and 1997 only, a manufacturer may apply to the Executive Officer for an
				  exemption from the 4.0 g/bhp-hr NOx standard, not to exceed 10% of the average
				  of the manufacturer's total urban bus sales in California for the three
				  preceding model years, upon providing technical justification and sales data
				  for each exemption applied for.
(B)
				  1998 through 2003 model year engines may generate averaging, banking, and
				  trading credits in accordance with the requirements for averaging, banking and
				  trading programs set forth in "California Exhaust Emission Standards and Test
				  Procedures for 1985 and Subsequent Model Heavy Duty Diesel Engines and
				  Vehicles" incorporated by reference in subdivision (c) of this
				  section.
(C) Manufacturers may
				  choose to certify 1998 through 2002 model year bus engines produced before
				  October 1, 2002, to an optional NOx emissions standard between 0.5 g/bhp-hr and
				  2.5 g/bhp-hr. A manufacturer may certify to any standard between the values of
				  2.5 g/bhp-hr and 0.5 g/bhp-hr, by 0.5 g/bhp-hr increments. Manufacturers may
				  not use engines certified to this optional NOx standard for any averaging,
				  banking, or trading program set forth in "California Exhaust Emission Standards
				  and Test Procedures for 1985 and Subsequent Model Heavy Duty Diesel Engines and
				  Vehicles" incorporated by reference in subdivision (c) of this
				  section.
(7) October 1,
				  2002, PM standard -- For diesel-fueled, dual-fuel, and bi-fuel bus engines
				  except for heavy-duty pilot ignition engines, the PM standard shall be 0.01
				  g/bhp-hr (0.01 PM g/bhp-hr in-use) for 2002 and subsequent model year engines
				  produced beginning October 1, 2002. Manufacturers may choose to meet this
				  standard with an aftertreatment system that reduces PM to 0.01
				  g/bhp-hr.
(8) October 2002-2006
				  optional standards -- Except for diesel-fueled, dual-fuel, and bi-fuel engines
				  but including heavy-duty pilot ignition engines, manufacturers may choose to
				  certify 2002-2006 model year bus engines produced beginning October 1, 2002, to
				  an optional 1.8 g/bhp-hr to 0.3 g/bhp-hr NOx plus NMHC standard, measured as
				  the arithmetic sum of the NOx and NMHC exhaust component certification values,
				  without restriction on individual component certification values; provided that
				  engines certified to this optional reduced-emission NOx plus NMHC standard may
				  not participate in any averaging, banking, or trading program set forth in the
				  test procedures document incorporated by reference in subdivision (c) of this
				  section. A manufacturer may certify to any standard between the values of 1.8
				  g/bhp-hr to 0.3 g/bhp-hr, by 0.3 g/bhp-hr NOx + NMHC increments. Manufacturers
				  certifying to this optional standard must also certify to a PM standard of
				  0.03, 0.02, or 0.01 g/bhp-hr.
(9)
				  October 2002-2003 optional standards for diesel-fueled, dual-fuel, and bi-fuel
				  engines except for heavy-duty pilot ignition engines -- Manufacturers may
				  choose to certify 2002-2003 model year diesel-fueled, dual-fuel, and bi-fuel
				  bus engines produced beginning October 1, 2002, to an optional 1.8 g/bhp-hr to
				  0.3 g/bhp-hr NOx plus NMHC standard, measured as the arithmetic sum of the NOx
				  and NMHC exhaust component certification values, without restriction on
				  individual component certification values; provided that engines certified to
				  this optional reduced-emission NOx plus NMHC standard may not participate in
				  any averaging, banking, or trading program set forth in the test procedures
				  document incorporated by reference in subdivision (c) of this section. A
				  manufacturer may certify to any standard between the values of 1.8 g/bhp-hr to
				  0.3 g/bhp-hr, by 0.3 g/bhp-hr NOx + NMHC increments. Manufacturers certifying
				  to this optional standard must also certify to a PM standard of 0.01
				  g/bhp-hr.
(10) 2004-2006 -- Except
				  as provided in paragraph (11), below, the required standard shall be 2.4
				  g/bhp-hr NOx + NMHC measured as the arithmetic sum of exhaust component
				  certification values for these pollutants, without restriction on individual
				  component values, 15.5 g/bhp-hr CO, and 0.05 g/bhp-hr PM (0.07 g/bhp-hr PM
				  in-use).
(A) Manufacturers may choose to
				  certify to a 2.5 g/bhp-hr optional combined NOx + NMHC standard, provided that
				  the NMHC exhaust component certification value shall not exceed 0.5
				  g/bhp-hr.
(B) Emissions averaging
				  may be used to meet the combined NOx + NMHC standard, the optional combined NOx
				  + NMHC standard set forth in paragraph (A), and the PM standard.
(C) The combined NOx + NMHC standard and the
				  optional combined NOx + NMHC standard described in paragraph (A) may serve as
				  the certification standard for the higher emitting fueling mode of an engine
				  certified under the dual fueling mode certification process set forth in
				  section 1956.8(a)(4),
				  Title 13, CCR.
(11)
				  2004-2006 -- For diesel-fueled, or dual-fuel, and bi-fuel urban bus engines
				  except for heavy-duty pilot ignition engines, the standards are 0.5 g/bhp-hr
				  NOx, 0.01 g/bhp-hr PM, 0.05 g/bhp-hr NMHC, 5.0 g/bhp-hr CO, and 0.01 g/bhp-hr
				  formaldehyde. As an option, manufacturers may choose to meet the NOx and PM
				  standards with a base engine that is certified to the standards in paragraph
				  (10) above, equipped with an aftertreatment system that reduces NOx to 0.5
				  g/bhp-hr and PM to 0.01 g/bhp-hr standards. The NMHC, CO, and formaldehyde
				  standards in this paragraph (11) shall still apply. Manufacturers shall be
				  responsible for full certification, durability, testing, and warranty and other
				  requirements for the base engine. For the aftertreatment system, manufacturers
				  shall not be subject to the certification durability requirements, or in-use
				  recall and enforcement provisions, but are subject to warranty provisions for
				  functionality.
(A) Engine manufacturers may
				  sell diesel-fueled, dual-fuel, or bi-fuel engines to any transit fleet exempted
				  by the Executive Officer under paragraphs (b)(8) and (c)(7) of section
				  2023.1, Title 13, CCR, from the
				  requirements of paragraphs (b)(5) and (c)(4) of section
				  2023.1, certified to the standards
				  in either paragraphs (9) or (10) above, provided that engines certified to the
				  standards in paragraph (10) must be certified to a 0.01 g/bhp-hr PM
				  standard.
(B) Manufacturers may
				  sell diesel-fueled hybrid-electric buses that are certified to a 1.8 g/bhp-hr
				  NOx, 0.01 g/bhp-hr PM, 0.5 g/bhp-hr NMHC, and 15.5 g/bhp-hr CO standard to any
				  transit agency that has received written authorization from the Executive
				  Officer pursuant to paragraph (c)(9) of section
				  2023.1, title 13, CCR. The
				  formaldehyde standard set forth in paragraph (11), above, shall not apply to
				  the HEBs sold pursuant to this subparagraph.