To determine an engine’s emissions, an owner/operator may use:

  1. Default SBCAPCD Diesel Engine Emission Factors – For use with older engines (see the first table presented below), or
  2. USEPA emission standards for Tier 1 – 4 engines (see the second table presented below)
Default SBCAPCD Diesel Engine Emission Factors
PollutantEmission FactorUnitsRef
PM1.0g/bhp-hr1
NOx (as NO2)14.1 g/bhp-hr1
NMHC1.12 g/bhp-hr1
NMHC+NOx15.22 g/bhp-hr1
CO3.0 g/bhp-hr1
SOx (as SO2)3.67 * wt %S g/bhp-hr2

basis: (1) USEPA AP-42, Table 3.3-1, (2) USEPA AP-42, Table 3.3-2, where S = wt  % of sulfur (eg, for S = 0.05 wt %: SOx = (3.67)*(0.05) = 0.183 g/bhp-hr.  Assume NMHC = ROC

USEPA Emission Standards for Tier 1 – 4 engines
 Engine Power (hp)Model Years Regulation Emission Standards (g/hp-hr)Year the Std Takes Effect
 HC a, cVHC b NOx a, c NMHC+NOx a CO a PM a
 50 to <75  1998-2003  Tier 1 6.901998
 2004-2007  Tier 2 0.400.39965.205.603.700.302004
 2008-2012  Tier 30.200.19983.33.503.700.302008
 2013 + Tier 40.200.19983.33.503.700.022013
>75 to <100  1998-2003  Tier 1 6.901997
 2004-2007  Tier 2 0.400.39965.205.603.700.302004
 2008-2011  Tier 3 0.200.19983.33.503.700.302008
 2012-2013 Tier 4 transitional0.140.13990.303.700.012012
 2014 + Tier 40.140.13990.303.700.012014
>100 to <175  1997-2002  Tier 1 6.901997
 2003-2006  Tier 2 0.400.39964.54.903.700.222003
 2007-2011  Tier 3 0.200.19982.83.003.700.222007
 2012-2013 Tier 4 transitional0.140.13990.303.700.012012
 2014 + Tier 40.140.13990.303.700.012014
>175 to <300  1996-2002  Tier 1 1.000.99906.908.500.401996
 2003-2005  Tier 2 0.400.39964.54.902.600.152003
 2006-2010  Tier 3 0.200.19982.83.002.600.152006
 2011-2013 Tier 4 transitional0.140.13990.302.600.012011
 2014 + Tier 40.140.13990.302.600.012014
>300 to <600  1996-2000  Tier 1 1.000.99906.908.500.401996
 2001-2005  Tier 2 0.300.29974.54.802.600.152001
 2006-2010  Tier 3 0.200.19982.83.002.600.152006
 2011-2013 Tier 4 transitional0.140.13990.302.600.012011
 2014 + Tier 40.140.13990.302.600.012014
>600 to <750  1996-2001  Tier 1 1.000.99906.908.500.401996
 2002-2005  Tier 2 0.300.29974.54.802.600.152002
 2006-2010  Tier 3 0.200.19982.83.002.600.152006
 2011-2013 Tier 4 transitional0.140.13990.302.600.012011
 2014 + Tier 40.140.13990.302.600.012014
 >750 except generator sets  2000-2005  Tier 1 1.000.99906.908.500.402000
 2006-2010  Tier 2 0.300.29974.54.802.600.152006
 2011-2014 Tier 4 transitional0.300.29972.602.600.082011
 2015 + Tier 40.140.13992.602.600.032015
 Generator sets >750 to <1200  2000-2005  Tier 1 1.000.99906.908.500.402000
 2006-2010  Tier 2 0.300.29974.54.802.600.152006
 2011-2014 Tier 4 transitional0.300.29972.602.600.082011
 2015 + Tier 40.140.13990.502.600.022015
 Generator sets >1200  2000-2005  Tier 1 1.000.99906.908.500.402000
 2006-2010  Tier 2 0.300.29974.54.802.600.152006
 2011-2014 Tier 4 transitional0.300.29970.502.600.082011
 2015 + Tier 40.140.13990.502.600.022015
Notes:

a Nonroad CI Engine Emission Standards from Title 13, California Code of Regulations, Section 2423 (ARB Executive Order “Std”).

b VHC = Total Hydrocarbons (THC) minus methane and ethane fractions.  Equivalent APCD standard. (Highlighted in Orange)  See Conversion Factors to Hydrocarbon Emission Components, Report No. NR-002a, US EPA, 5/2003.  {VHC = ROC}

c Tier 2 and Tier 3 HC and NOx equivalent standards used to determine the NMHC + NOx standard.  (Highlighted in blue)

For more information or assistance, call or email Mike Goldman at (805) 961-8821.

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