Cal. Code Regs. tit. 13, § 2423.0.1
(a) This section shall be applicable to new heavy-duty off-road compression-ignition engines, produced on or after January 1, 1996, and all other new 2000 and later model year off-road compression-ignition engines. For the purposes of this section, these engines shall be called “compression-ignition engines.”
(B) Exhaust emissions from new off-road compression-ignition engines, as sold in this state and as appropriate based on model year and maximum engine power, shall not exceed the levels contained in Table 1b, with respect to steady-state testing, transient testing, and, after application of the criteria in Table 1c, not-to-exceed testing, as applicable. Other compliance options are permissible as provided in the 2008 and Later Test Procedures.
Table 1b. -- Tier 4 Exhaust Emission Standards (grams per kilowatt-hour)
Maximum Engine Power
Model Year
Type
PM
NMHC + NOx
NMHC grams per kilowatt-hour
NOx
CO
kW<8 1
2008 and later
Final
0.40 2
7.5
-
-
8.0
8≤kW<19 1
6.6
19≤kW<37 1
2008-2012
Interim
0.30
7.5
-
-
5.5
2013 and later
Final
0.03
4.7
37≤kW<56 3
2008-2012
Interim
0.30
4.7
-
-
5.0
2013 and later
Final
0.03
56≤kW<75
2012-2014 4
Phase-In
0.02
-
0.19
0.40
5.0
Phase-Out
4.7
-
-
or/ Alt NOx
-
0.19
3.4 5
or/ Alt NOx+NMHC 8
3.5 5
-
-
2015 and later
Final
-
0.19
0.40
75≤kW<130
2012-2014 4
Phase-In
0.02
-
0.19
0.40
5.0
Phase-Out
4.0
-
-
or/ Alt NOx
-
0.19
3.4 5
or/ Alt NOx+NMHC 8
3.5 5
-
-
2015 and later
Final
-
0.19
0.40
130≤kW≤560
2011-2013
Phase-In
0.02
-
0.19
0.40
3.5
Phase-Out
4.0
-
-
or/ Alt NOx
-
0.19
2.0
or/ Alt NOx+NMHC 8
2.1
-
-
2014 and later
Final
-
0.19
0.40
560 kW<GEN 6≤900 kW
2011-2014
Interim
0.10
-
0.40
3.5
3.5
2015 and later
Final
0.03
0.19
0.67
GEN>900 kW
2011-2014
Interim
0.10
-
0.40
0.67
3.5
2015 and later
Final
0.03
0.19
ELSE 7>560 kW
2011-2014
Interim
0.10
-
0.40
3.5
3.5
2015 and later
Final
0.04
0.19
Notes:
1 Propulsion marine compression-ignition engines below 37 kW are not subject to Tier 4 standards or requirements. All previously adopted requirements remain applicable for these engines.
2 The Tier 4 PM standard for hand-start, air cooled, direct injection engines below 8 kW is 0.60 g/kW-hr, but is not required until 2010.
3 Engine families in this power category may alternately meet Tier 3 PM standards from 2008-2011 in exchange for introducing final PM standards in 2012.
4 Manufacturers have the option of complying with the Tier 4 standards over a two year period at 50% per year using banked Tier 2 credits or over a three year period at 25% per year without the use of Tier 2 credits. The three year phase-in period is shown. The 2014 model year cannot extend beyond December 30, 2014, when the 3 year phase-in option is used.
5 Manufacturers may comply with the standards during the transitional implementation years using either a phase-in/phase-out approach or by using the Alternate NOx approach. The three year 25% alternate NOx standard is shown in the table. The two year 50% phase-in NOx standard would be 2.3 g/kW-hr.
6 “GEN” refers to generator engines only.
7 “ELSE” refers to all mobile machinery excluding generator engines.
8 An ALT NOx+NMHC standard equal to 0.5 g/kW-hr is available for one additional model year following the last model year of the ALT NOx+NMHC phase-in shown in the table.
Table 1c. -- Criteria for Determining NTE Limits 1
Pollutant
Apply NTE Multiplier of 1.25 when ...
Apply NTE Multiplier of 1.50 when ...
NOx
NOx Standard or FEL≥2.5 g/kW-hr
NOx Standard 2 or FEL<2.5 g/kW-hr
NMHC
NOx Standard or FEL≥2.5 g/kW-hr
NOx Standard 2 or FEL<2.5 g/kW-hr
NMHC + NOx
NMHC+NOx Standard or FEL≥2.7 g/kW-hr
NMHC + NOx Standard 2 or FEL<2.7 g/kW-hr
PM
PM Standard or FEL≥0.07 g/kW-hr
PM 2 Standard or FEL 3<0.07g/kW-hr
CO
Always
Never
Notes:
1 Other provisions described in the 2008 and Later Test Procedures may affect the calculation of NTE limits.
2 Engines must be certified to these standards without the use of ABT credits.
3 For engines certified to a PM FEL less than or equal to 0.01 g/kW-hr, the PM NTE limit shall be 0.02 g/kW-hr.
(2) Manufacturers may elect to include engine families in one of two averaging, banking, and trading (ABT) programs, corresponding to the engine family's model year and emissions categorization. The provisions of these separate ABT programs are specified in Part 89, Subpart C of the 2000 Plus Limited Test Procedures and Part 1039, Subpart H of the 2008 and Later Test Procedures.
(A) For engine families subject to the 2000 Plus Limited Test Procedures, the manufacturer must set a family emission limit (FEL) not to exceed the levels contained in Table 2a. The FEL established by the manufacturer serves as the emission standard for that engine family. Table 2a follows:
Table 2a -- Upper Limit for Tier 1, Tier 2, and Tier 3 Family Emission Limits (FEL) (grams per kilowatt-hour)
Maximum Rated Power (kW)
Tier
Model Year
NOx
NMHC + NOx
PM FEL
kW<8
Tier 1
2000-2004
16.0
1.2
Tier 2
2005-2007
10.5
1.0
8≤kW<19
Tier 1
2000-2004
16.0
1.2
Tier 2
2005-2007
9.5
0.80
19≤kW<37
Tier 1
2000-2003
16.0
1.2
Tier 2
2004-2007
9.5
0.80
37≤kW<56
Tier 1
2000-2003
14.6
Tier 2
2004-2007
11.5
1.2
Tier 3 1
2008-2011
7.5
1.2
56≤kW<75
Tier 1
2000-2003
14.6
Tier 2
2004-2007
11.5
1.2
Tier 3
2008-2011
7.5
1.2
75≤kW<130
Tier 1
2000-2002
14.6
Tier 2
2003-2006
11.5
1.2
Tier 3
2007-2011
6.6
1.2
130≤kW<225
Tier 1
2000-2002
14.6
Tier 2
2003-2005
10.5
0.54
Tier 3
2006-2010
6.6
0.54
225≤kW<450
Tier 1
2000
14.6
Tier 2
2001-2005
10.5
0.54
Tier 3
2006-2010
6.4
0.54
450≤kW≤560
Tier 1
2000-2001
14.6
Tier 2
2002-2005
10.5
0.54
Tier 3
2006-2010
6.4
0.54
kW>560
Tier 1
2000-2005
14.6
Tier 2
2006-2010
10.5
0.54
1 Manufacturers may optionally certify engine families to the interim Tier 4 FEL caps in Table 2b for this power category through 2012.
(B) For engine families subject to the 2008 and Later Test Procedures, the manufacturer must set a family emission limit (FEL) not to exceed, as applicable, the levels contained in Table 2b. Three distinct FEL types (primary, interim, and alternate) are available conditionally. Primary FEL types are applicable to all power categories indefinitely, whereas interim and alternate FEL types are of variable duration and may be selectively applied to total or partial engine family production volumes as described in the 2008 and Later Test Procedures. The FEL established by the manufacturer serves as the emission standard for that engine family, and is used for determining NTE limits in conjunction with the criteria in Table 1c. Temporary compliance adjustment factors, as explained in the 2008 and Later Test Procedures, shall be applied by the manufacturer to compensate for the use of transitional alternate FELs (Type ALT 20% in Table 2b) when calculating emission credits. Table 2b follows:
Table 2b -- Upper Limit for Tier 4 Family Emission Limits (FELs) and Alternate Allowances
Part 1
Maximum Engine Power
FEL Type
Model Year
PM
NOx grams per kilowatt-hour
NMHC + NOx
kW<8
Primary
2008 and later
0.80
-
10.5
8≤kW<19
Primary
2008 and later
0.80
-
9.5
19≤kW<37
Interim
2008-2012
0.60
-
9.5
Primary
2013 and later
0.05
-
7.5
ALT 20% 1
2013-2016 3
0.30
-
7.5
ALT 5% 2
2017 and later 3
37≤kW<56
Interim
2008-2012 3
0.40
-
7.5
Primary
2013 and later 3
0.05
-
7.5
ALT 20%
2013-2016 3
0.30
-
7.5
ALT 5%
2017 and later 3
56≤kW<75
Phase-in
2012-2013/2014 5
0.04
0.80
-
Phase-out
-
7.5
ALT NOx Std 4
2012-2013
0.04
3.0 7
-
2012-2014
4.4
ALT NOx+NMHC Std 4
2012-2013/2014 5
0.04
-
4.7 7
Primary
2014/2015 5 and later
0.04
0.80
-
ALT 20% PM
2012-2015
0.40
-
ALT 20% NOx
2012-2015 6
4.4
-
ALT 20% NOx+NMHC Std
2012-2015 6
-
-
4.7
ALT 5%
2016 and later
0.40
4.4
-
Notes:
1 This alternate FEL option is transitional for the four years specified and applies to at most 20% of a manufacturer's U.S. directed population of engine families per year.
2 This alternate FEL option is available indefinitely, but only applies to 5% of a manufacturer's U.S. directed population of engine families per year.
3 These dates correspond to the compliance option of meeting interim standards in 2008; else the primary and alternate FEL caps would begin and end one year earlier, and 2008-2011 engines would not be eligible for participation in the Tier 4 ABT program.
4 Two alternate NOx standards and corresponding FEL caps are available for this category with corresponding alternate phase-in options.
5 The effective date of the primary FEL cap follows the phase-in period and use of banked Tier 2 NOx credits of the selected NOx FEL cap.
6 For manufacturers certifying engines in this power category using a percentage phase-in/phase-out approach instead of the ALT NOx or ALT NOx+NMHC Standards in Table 1b of § 2423(b)(1)(B), the alternate NOx and NOx+NMHC FEL caps in the table apply only in the 2014-2015 model years if certifying in accordance with the provisions in § 1039.102(d)(1) of the 2011 and Later Test Procedures, and only in the 2015 model year if certifying under 1039.102(d)(2) of the 2016 and later Test Procedures.
7 If neither the alternate phase-in option nor banked Tier 2 credits are used, either NOx standard and corresponding FEL may be applied for this category.
Table 2b -- Upper Limit for Tier 4 Family Emission Limits (FELs) and Alternate Allowances
Part 2
Maximum Engine Power
FEL Type
Model Year
PM
NOx grams per kilowatt-hour
NMHC + NOx
75≤kW<130
Phase-in
2012-2013/2014 5
0.04
0.80
-
Phase-out
-
6.6
ALT NOx Std 4
2012-2013
3.0 7
-
2012-2014
3.8
-
ALT NOx+NMHC Std 4
2012-2013/2014 5
-
4.0 7
Primary
2014/2015 5 and later
0.80
-
ALT 20% PM
2012-2015
0.30
-
ALT 20% NOx
2012-2015 6
3.8
-
ALT 20% NOx+NMHC Std 4
2012-2015 6
-
-
4.0
ALT 5%
2016 and later
0.30
3.8
-
130≤kW≤560
Phase-in
2011-2013
0.04
0.80
-
Phase-out
-
6.6/6.4 8
ALT NOx Std
2011-2013
2.7
-
ALT NOx+NMHC Std
2011-2013
-
4.0
Primary
2014 and later
0.80
-
ALT 20% PM
2011-2014
0.20
-
ALT 20% NOx
2011-2014 9
3.8
-
ALT 20% NOx+NMHC Std
2011-2014 9
-
-
4.0
ALT 5%
2015 and later
0.20
3.8
-
GEN>560kW
Interim
2011-2014
0.20
6.2
-
Primary
2015 and later
0.05
1.07
-
ALT 20%
2015-2018
0.10
3.5
-
ALT 5%
2019 and later
-
ELSE>560kW
Interim
2011-2014
0.20
6.2
-
Primary
2015 and later
0.07
-
ALT 20%
2015-2018
0.10
-
ALT 5%
2019 and later
-
Notes:
4 Two alternate NOx standards and corresponding FEL caps are available for this category with corresponding alternate phase-in options.
5 The effective date of the primary FEL cap follows the phase-in period of the selected NOx FEL cap.
6 For manufacturers certifying engines in this power category using a percentage phase-in/phase-out approach instead of the ALT NOx or ALT NOx+NMHC Standards in Table 1b of § 2423(b)(1)(B), the alternate NOx and NOx+NMHC FEL caps in the table apply only in the 2014-2015 model years if certifying in accordance with the provisions in § 1039.102(d)(1) of the 2011 and Later Test Procedures, and only in the 2015 model year if certifying under § 1039.102(d)(2) of the 2016 and later Test Procedures.
7 If neither the alternate phase-in option nor banked Tier 2 credits are used, either NOx standard and corresponding FEL may be applied for this category.
8 The phase-out NMHC + NOX FEL cap is 6.6 g/kW-hr for engines <225 kW, and 6.4g/kW-hr for engines ≥225kW in this category.
9 For manufacturers certifying engines in this power category using the percentage phase-in/phase-out approach instead of the ALT NOx standard of the ALT NOx+NMHC standard in Table 1b of § 2423(b)(1)(B), the ALT NOx and ALT NOx+NMHC FEL caps in the table apply only for the 2014 model year.
(C) Split family provision. For generating or using credits in the 56≤kW≤560 power categories during the phase-in of Tier 4 standards, engine manufacturers may elect to split an engine family into two subfamilies (e.g., one which uses credits and one which generates credits for the same pollutant). The engine manufacturer must indicate in the application for certification that the engine family is to be split, and may calculate emission credits relative to different emissions standards (i.e., phase-in and phase-out standards) for different sets of engines within the engine family, but must certify the engine family to a single set of standards and FELs. The engine manufacturer shall calculate NMHC + NOx emission credits by adding the NOx FEL to the NMHC phase-in standard for comparison with the applicable NMHC + NOx phase-out standard. Any engine family certified under the provisions of this paragraph (C) must meet the applicable phase-in standard for NMHC. The engine manufacturer shall be responsible for assigning the number and configurations of engines within the respective subfamilies before the due date of the final report required in Part 1039, Subpart H of the 2008 and Later Test Procedures. The same label must be applied to each engine in the family, and must include the NOx FEL to which the engine is certified.
(3)(A) The opacity of smoke emissions from new 1996 through 1999 model year heavy-duty off-road compression-ignition engines 175 to 750 horsepower, inclusive, or from all new 2000 and later model year compression-ignition engines sold in this state, shall not exceed, based on the applicable measurement techniques specified in Part 89, Subpart B of the 2000 Plus Limited Test Procedures and Part 1039, Subpart B of the 2008 and Later Test Procedures, the following:
(B) The following engines are exempt from the requirements of this paragraph (3):
(4) Low-emitting Blue Sky Series engines requirements.
(A) Voluntary standards. Engines subject to the standards in (b)(1)(A) may be designated “Blue Sky Series” engines by meeting the voluntary standards contained in Table 3, which apply to all certification and in-use testing. Blue Sky Series engines shall not be included in the Averaging, Banking, and Trading program. Table 3 follows:
Table 3. -- Voluntary Emission Standards (grams per kilowatt-hour)
Maximum Rated Power (kW)
NMHC + NOx
PM
kW<8
4.6
0.48
8≤kW<19
4.5
0.48
19≤kW<37
4.5
0.36
37≤kW<75
4.7
0.24
75≤kW<130
4.0
0.18
130≤kW≤560
4.0
0.12
kW>560
3.8
0.12
(C) Test Procedures. NOx, NMHC, and PM emissions are measured using the procedures set forth in 40 CFR part 86, subpart N (July 1, 1999), which is incorporated by reference, in lieu of the procedures set forth in subpart E of the 2000 Plus Limited Test Procedures. CO emissions may be measured using procedures set forth in 40 CFR part 86, subpart N (July 1, 1999), or in subpart E of the 2000 Plus Limited Test Procedures. Manufacturers may use an alternate procedure to demonstrate the desired level of control if approved in advance by the Executive Officer. Engines meeting the requirements to qualify as Blue Sky Series engines must be capable of maintaining a comparable level of emission control when tested using the procedures set forth in both Section 89.112(c) and subpart E of the 2000 Plus Limited Test Procedures. The numerical emission levels measured using the procedures from subpart E of the 2000 and Plus Limited Procedures may be up to 20 percent higher than those measured using procedures from 40 CFR part 86, subpart N (July 1, 1999), and still be considered comparable.
(5)(A) No crankcase emissions shall be discharged into the ambient atmosphere from any new 1996-1999 model year heavy-duty off-road compression-ignition engine or any Tier 2 or later off-road compression-ignition engine subject to the 2000 Plus Limited Test Procedures. This provision does not apply to petroleum-fueled diesel cycle engines using turbochargers, pumps, blowers, or superchargers for air induction.
(6) Engine manufacturers that voluntarily certify engines to the Tier 4 standards in Table 1b earlier than required under this article may, according to the provisions in the 2008 and Later Test Procedures, generate additional ABT credits, or as an alternative, offset future Tier 4 compliance requirements should the equipment manufacturer that was provided the engine decline to use its early introduction incentives according to the provisions in Section 2423(d)(9). Table 4, as follows, summarizes the incentives for the early introduction of Tier 4 engines and some of the conditions that determine eligibility.
Table 4. -- Early Introduction Incentives for Engine Manufacturers
Early Introduction
Power Category
Qualifying Standards 1 grams per kilowatt-hour
Per Engine Incentive
Final Tier 4
19≤kW<56
0.03 PM
3 for 2
PM-Only 2
56≤kW<560
0.02 PM
PM-Only
Final Tier 4 All
19≤kW<56
0.03 PM/4.7 NMHC + NOx
3 for 2
56≤kW≤560
0.02 PM/0.40 NOx/0.19 NMHC
GEN>560
0.03 PM/0.67 NOx/0.19 NMHC
ELSE≥560
0.04 PM/3.5 NOx/0.19 NMHC
Ultra Low NOx
kW≥19
Final Tier 4 PM & NMHC/0.20 NOx
2 for 1
Notes:
1 All engines must meet the Tier 4 crankcase emissions requirements. Engines must certify using all test and other requirements otherwise required for final Tier 4 standards such as for transient and not-to-exceed limits.
2 Offsets must be earned prior to the start of phase-in requirements (prior to 2013 for 19≤kW<56 engines, prior to 2012 for 56≤kW<130 engines, prior to 2011 for 130≤kW≤560 engines, prior to 2015 for >560 kW engines)
(7) Provisions for small-volume manufacturers. Small-volume engine manufacturers are entitled to special compliance provisions under this paragraph, but must notify the Executive Officer in writing before January 1, 2008, of the intent to use the provisions.
(A) Small-volume engine manufacturers may delay complying with certain otherwise applicable Tier 4 emission standards and requirements as described in the following table:
Table 5. -- Small-Volume Engine Manufacturer Provisions
Maximum Engine Power
Temporary Relief Replacement Standards
Delay End Date (Model Year)
kW<19
Tier 2
2011
19≤kW<37
Interim Tier 4
2016
37≤kW<56
See paragraph (7)(B) of this section for special provisions that apply for engines in this power range.
56≤kW<130
Tier 3
2015
(B) The provisions of this paragraph (7) for engines 37≤kW<56 are applicable per one of the following options:
(D) For engines not in the 19≤kW<56 power range, small volume engine manufacturers must meet the following conditions for the model years in which compliance with the otherwise applicable standards under this paragraph (7) is delayed:
(E) For engines in the 19≤kW<56 power range, small-volume engine manufacturers must meet the following conditions for the model years in which compliance with the otherwise applicable standards under this paragraph (7) is delayed:
(9) NTE deficiencies. A manufacturer may petition the Executive Officer to accept an off-road compression-ignition engine as compliant with the NTE requirements specified in the 2008 and Later Test Procedures even though specific elements of those requirements may not be fully met. Such grants of compliance, otherwise known as deficiencies, shall be limited to engines that have functioning emission-control hardware capable of allowing the engine to comply with the NTE limits. Deficiencies shall be granted by the Executive Officer according to the following stipulations:
(12) Defeat devices. Engines equipped with a defeat device shall not be certified for sale in California. A defeat device is a component or system that reduces the effectiveness of emission controls under conditions that the engine may reasonably be expected to encounter during normal operation and use. This prohibition does not apply to auxiliary-emission control devices identified in the certification application if one of more of the following is true:
(C) The auxiliary-emission control device only reduces the effectiveness of emissions control during engine starting.
(c)(1) The test procedures for determining certification and compliance with the standards for gaseous exhaust emissions from new 1996-1999 heavy-duty off-road compression-ignition engines sold in the state are set forth in the 1996-1999 Heavy-Duty Test Procedures.
(2)(A) The test procedures for determining certification and compliance with the standards for gaseous exhaust emissions and the standards for opacity of smoke emissions from new 2000 model year and later off-road compression-ignition engines for which the standards in paragraph (b)(1)(A) are applicable, and sold in the state, are set forth in the 2000 Plus Limited Test Procedures.
(b)(1)(A) Exhaust emissions from new off-road compression-ignition engines, as sold in this state and as appropriate based on model year and maximum rated power, shall not exceed the levels contained in Table 1a with respect to steady-state testing. Table 1a follows:
Table 1.a -- Tier 1, Tier 2, and Tier 3 Exhaust Emission Standards (grams per kilowatt-hour)
Maximum Rated Power (kW) 1
Tier
Model Year
NOx 2
HC 3
NMHC + NOx 4
CO 5
PM 6
kW<8
Tier 1
2000-2004
--
--
10.5
8.0
1.0
Tier 2
2005-2007 7
--
--
7.5
8.0
0.80
8≤kW<19
Tier 1
2000-2004
--
--
9.5
6.6
0.80
Tier 2
2005-2007 7
--
--
7.5
6.6
0.80
19≤kW<37
Tier 1
2000-2003
--
--
9.5
5.5
0.80
Tier 2
2004-2007 7
--
--
7.5
5.5
0.60
37≤kW<56
Tier 1
2000-2003
9.2
--
--
--
--
Tier 2
2004-2007
--
--
7.5
5.0
0.40
Tier 3 8
2008-2011
--
--
4.7
5.0
0.40
56≤kW<75
Tier 1
2000-2003
9.2
--
--
--
--
Tier 2
2004-2007
--
--
7.5
5.0
0.40
Tier 3
2008-2011
--
--
4.7
5.0
0.40
75≤kW<130
Tier 1
2000-2002
9.2
--
--
--
--
Tier 2
2003-2006
--
--
6.6
5.0
0.30
Tier 3
2007-2011
--
--
4.0
5.0
0.30
130≤kW<225
Tier 1
1996-2002
9.2
1.3
--
11.4
0.54
Tier 2
2003-2005
--
--
6.6
3.5
0.20
Tier 3
2006-2010
--
--
4.0
3.5
0.20
225≤kW<450
Tier 1
1996-2000
9.2
1.3
--
11.4
0.54
Tier 2
2001-2005
--
--
6.4
3.5
0.20
Tier 3
2006-2010
--
--
4.0
3.5
0.20
450≤kW≤560
Tier 1
1996-2001
9.2
1.3
--
11.4
0.54
Tier 2
2002-2005
--
--
6.4
3.5
0.20
Tier 3
2006-2010
--
--
4.0
3.5
0.20
kW>560
Tier 1
2000-2005
9.2
1.3
--
11.4
0.54
Tier 2
2006-2010
--
--
6.4
3.5
0.20
1 kW means kilowatts.
2 NOx means Oxides of Nitrogen.
3 HC means Hydrocarbons.
4 NMHC + NOx means Non-Methane Hydrocarbons plus Oxides of Nitrogen.
5 CO means Carbon Monoxide.
6 PM means Particulate Matter.
7 Tier 2 standards for propulsion marine compression-ignition engines below 37 kW remain in effect beyond the 2007 end date.
8 Manufacturers may optionally certify engine families to the interim Tier 4 standards in Table 1b for this power category through 2012.
(d) Implementation flexibility for equipment and vehicle manufacturers and post-manufacture marinizers. For a limited time, off-road equipment and vehicle manufacturers and post-manufacture marinizers may produce equipment with engines that are subject to less stringent emission standards than required by Tables 1a and 1b for new 2000 model year and later off-road equipment and vehicles and marine compression-ignition engines, subject to the requirements of paragraph (e) of this section. Separate provisions are provided for equipment with engines subject to the 2000 Plus Limited Test Procedures versus equipment with engines subject to the 2008 and Later Test Procedures, and are identified accordingly in the following subsections. Only manufacturers that have primary responsibility for designing and manufacturing equipment, and have manufacturing procedures for installing engines in equipment, are eligible to participate in the equipment manufacturer flexibility program provided by the 2008 and Later Test Procedures. Equipment manufacturers participating in this flexibility program must comply with the notification and reporting requirements specified in Section 2423(d)(7). Engines produced for this flexibility program using FELs greater than the applicable standards must be offset with sufficient ABT credits. The following allowances apply separately to each engine power category subject to standards under Section 2423(b)(1):
(1) Percent-of-production allowances.
(C) Equipment subject to the 2008 and Later Test procedures. A manufacturer may produce equipment and vehicles with engines that are exempt from meeting current model year emission standards for a portion of its California-directed production volume. These percent-of-production flexibility allowances must be used within one of the seven-year flexibility usage periods specified in Table 6 for each applicable power category, provided that the seven-year sum of the U.S.-directed portion of the manufacturer's percent-of-production flexibility allowances does not exceed 80 percent, expressed in cumulative yearly percentage increments, except as provided for in paragraph (d)(6) or (f). Equipment used as percent-of-production flexibility allowances must contain only engines that have been certified to, at least, the standards listed in Table 6, corresponding to the flexibility usage period selected by the manufacturer. All flexibility allowances for a power category must be used within the same flexibility usage period.
Table 6. -- Tier 4 Flexibility Allowance Options
Power Category
7 Year Usage Period
Flexibility Standard
<19 kW
2008-2014
Tier 2
19≤kW<56
2008-2014 1
Tier 3 2
2012-2018
2008 Interim Tier 4
56≤kW<130
2012-2018
Tier 3
2014-2020
2012 Interim Tier 4
130≤KW≤560
2011-2017
Tier 3
2014-2020
2011 Interim Tier 4
>560 kW
2011-2017
Tier 2
2015-2021
2011 Interim Tier 4
Notes:
1 This usage period is not available for allowances greater than or equal to 37 kW unless interim Tier 4 standards have been met starting in 2008.
2 Flexibility allowances under 37kW may contain engines certified to the Tier 2 standards.
(2)(A) Small volume allowances subject to the 2000 Plus Limited Test Procedures. An off-road equipment or vehicle manufacturer or post-manufacture marinizer may exceed the production percentages in paragraphs (d)(1)(A) and (B) of this section for a portion of its California-directed production, provided that in each regulated power category the manufacturer's total number of U.S.-directed off-road equipment and vehicles and marine diesel applications that contain engines which are exempt from meeting current model year emission standards over the years in which the percent-of-production allowance applies:
(B) Small volume allowances subject to the 2008 and Later Test Procedures. As an alternative to the percent-of-production allowance in Section 2423(d)(1)(C), an off-road equipment or vehicle manufacturer may produce equipment with engines that are exempt from meeting current model year emission standards for a portion of its California-directed production volume, provided that the exempt equipment is a subset of the manufacturer's U.S.-directed volume of exempt equipment and the manufacturer is in compliance with the following provisions:
1. Single engine family provision. A manufacturer may claim up to 700 U.S.-directed flexibility allowances within a power category during one of the seven-year flexibility usage periods specified in Table 6, but no more than 200 allowances in a single year within a power category, except as provided for in paragraph(d)(6) or (f). Engines within a power category that are used in these flexibility allowances must be from a single engine family within a given year.
b. Multiple engine family provision for flexibility allowances at or above 130 kW. A manufacturer may produce up to 350 U.S.-directed flexibility allowances within a power category during one of the seven-year flexibility usage periods specified in Table 6, but no more than 100 allowances in a single year within a power category, except as provided for in paragraph (d)(6) of (f). Engines within a power category that are used in these flexibility allowances may be from multiple engine families within a given year.
(3)(A) Inclusion of previous-tier engines. Off-road equipment and vehicles and marine diesel engines built with previous tier or noncertified engines under the existing inventory provisions of the 2000 Plus Limited Test Procedures (40 CFR Section 89.1003(b)(4)) need not be included in determining compliance with paragraphs (d)(1)(A) and (B) and (d)(2)(A) of; this section.
2.a. Multiple engine family provision for flexibility allowances below 130 kW. A manufacturer may claim up to 525 U.S.-directed flexibility allowances within a power category during one of the seven-year flexibility usage periods specified in Table 6, but no more than 150 allowances in a single year within a power category, except as provided for in paragraph (d)(6) or (f). Engines within a power category that are used in these flexibility allowances may be from multiple engine families within a given year.
(4) Early-use of flexibility allowances. Manufacturers may start using a portion of the flexibility allowances in Subsections (d)(1)(C) and (d)(2)(B) for equipment and vehicles containing engines not yet subject to the Tier 4 standards, provided that the seven-year period for using flexibility allowances under the 2000 Plus Limited Test Procedures flexibility program has expired. All equipment and vehicles claimed as flexibility allowances under this early-use provision must contain engines that have been certified to, at least, the Tier 1 standards. Manufacturers must count these Tier 2 or Tier 3 equipment and vehicles toward the total percentage, or number, of flexibility allowances permitted under the provisions of Sections (d)(1)(C) and (d)(2)(B). The maximum cumulative early-use allowance is 10 percent under the percent-of-production provision in Section (d)(1)(C), or 100 units under the small volume provision in Section (d)(2)(B). Table 7 shows the applicable years for using early-use flexibility allowances. Table 7 follows:
Table 7. -- Years for Early-Use Flexibility Allowances
Maximum Engine Power
Calendar Years
kW<19
2007
19≤kW<37
2006-2011
37≤kW<56
2011
56≤kW<75
2011
75≤kW<130
2010-2011
130≤kW<225
2010
225≤kW<450
2008-2010
450≤kW≤560
2009-2010
>560 kW
--
(5) Labeling requirements. Allowances claimed under the Tier 2/3 or Tier 4 equipment flexibility programs must be labeled, as appropriate, per the following:
(A) Engine labeling. Except for engines used in flexibility allowances prior to January 1, 2007, engine manufacturers shall meet the labeling requirements provided in Section 2424 with the following substitutions:
For flexibility engines meeting previous year emission requirements, the engine manufacturer shall substitute the following for the statement of compliance required in Sections 2424(c)(1)(E)6 and 2424(c)(2):
“THIS ENGINE COMPLIES WITH CALIFORNIA EMISSION REQUIREMENTS UNDER 13 CCR 2423(d). SELLING OR INSTALLING THIS ENGINE FOR ANY PURPOSE OTHER THAN FOR THE EQUIPMENT FLEXIBILITY PROVISIONS CITED MAY BE A VIOLATION OF STATE LAW SUBJECT TO CIVIL PENALTY.” [Insert Engine Family Name]
For flexibility engines less than 37 kW and not subject to emission requirements under the Tier 2/3 program, the engine manufacturer shall substitute the following for the statement of compliance required in Section 2424(c)(1)(E)6:
“THIS ENGINE QUALIFIES FOR USE IN EQUIPMENT RATED BELOW 37 KW BY PROVISION OF 13 CCR 2423(d). SELLING OR INSTALLING THIS ENGINE FOR ANY PURPOSE OTHER THAN FOR THE EQUIPMENT FLEXIBILITY PROVISIONS CITED MAY BE A VIOLATION OF CALIFORNIA LAW SUBJECT TO CIVIL PENALTY.”
As an alternative for flexibility engines produced under the Tier 2/3 program, and for which the engine manufacturer offers proof to the Executive Officer that the otherwise required statements of compliance in this subsection would be unduly burdensome or costly to implement, engine manufacturers may instead use the following:
“THIS ENGINE CONFORMS TO CALIFORNIA OFF-ROAD COMPRESSION-IGNITION ENGINE REGULATIONS UNDER 13 CCR 2423(d).” [Insert Engine Family Name if Certified]
These revised statements of compliance do not preclude the referencing of similar federal requirements that would be satisfied simultaneously by meeting the provisions of Section 2423(d). Furthermore, the Executive Officer may, upon request, approve alternate labeling specifications that are equivalent to the specifications in this subsection.
(B) Equipment Labeling. For all allowances claimed under the Tier 4 flexibility program, equipment manufacturers shall affix a permanent label to the engine, or to a readily visible section of the equipment that cannot be easily removed. The label shall be in the English language, shall supplement the manufacturer's emission control information label, and shall include the following information:
5. The following statement:
“THIS EQUIPMENT [or identify the type of equipment] HAS AN ENGINE THAT MEETS CALIFORNIA EMISSION STANDARDS UNDER 13 CCR 2423(d).”
This label content does not preclude the referencing of similar federal requirements that would be satisfied simultaneously by meeting the provisions of Section 2423(d).
(6) Technical hardship allowances. Equipment manufacturers may apply for additional flexibility allowances should extreme and unusual circumstances occur leading to technical obstacles in complying with the Tier 4 requirements. A manufacturer may request additional allowances for power categories 19≤kW≤560 if it claims allowances under the provisions of Section 2423(d)(1)(C), but may only request additional allowances for power categories 19≤kW<56 if it claims allowances under the provisions of Section 2423(d)(2)(B). Additional flexibility allowances shall not be provided when the engine and equipment are produced by the same manufacturer, or affiliate. The Executive Officer shall review requests for additional flexibility allowances according to the following stipulations:
(B) Manufacturers applying for additional flexibility allowances must do so in writing to the Chief of the Mobile Source Operations Division, or designee, prior to the earliest date in which the applying manufacturer would be in violation of Section 2423(b)(1). All applications shall provide, at a minimum, the following information:
8. An estimation of the number of additional allowances needed for each equipment model covered by the request, subject to Sections 2423(d)(6)(C) and (d)(6)(D) below.
Notwithstanding, the Executive Officer may require additional information as deemed necessary before making a determination for relief.
(C) The following limits shall apply for additional flexibility allowances granted in connection to the percent-of-production provisions in Section 2423(d)(1)(C):
(D) The following limits shall apply for additional flexibility allowances granted in connection to the small volume provisions in Section 2423(d)(2)(B):
1. Only small equipment manufacturers, as defined below, that have not been granted additional flexibility allowances for the 19≤kW<56 power category under Section 2423(d)(6)(C), are eligible to request additional flexibility allowance under this provision.
“Small equipment manufacturer,” for the purpose of this provision, means a federally defined small-business equipment manufacturer that had an annual U.S.-directed production volume of equipment using off-road diesel engines 19≤kW<56 of no more than 3,000 units in 2002 and all earlier calendar years, and has 750 or fewer employees (500 or fewer employees for nonroad equipment manufacturers that produce no construction equipment or industrial trucks). For manufacturers owned by a parent company, the production limit applies to the production of the parent company and all its subsidiaries and the employee limit applies to the total number of employees of the parent company and all its subsidiaries.
(7) Notification and reporting requirements for using Tier 4 flexibility allowances. As a prerequisite to using any Tier 4 flexibility allowances, the equipment manufacturer shall notify the ARB of its intent to use such allowances. The manufacturer shall also send an annual report after each year that flexibility allowances have been used to verify that the allowances claimed do not exceed the number of allowances permitted.
(A) Before January 1 of the first year that flexibility provisions will be used, a written notice informing ARB of the manufacturer's intent to use flexibility allowances must be sent to the Chief of the Mobile Source Operations Division, or designee, containing the following information:
(9) Early introduction incentives for equipment manufacturers. In addition to the equipment flexibility allowances provided in Subsections (d)(1)(C) and (d)(2)(B), equipment manufacturers, as provided in the 2008 and Later Test Procedures, may earn additional allowances for the early introduction of equipment with engines meeting the Tier 4 standards in Table 1b. Equipment manufacturers installing engines at or above 19 kW that comply with the final Tier 4 PM and NOx standards could earn one flexibility allowance for each early Tier 4 compliant engine used in its equipment. Equipment manufacturers installing engines 56≤kW≤560 that comply with the final Tier 4 PM standard and the alternative NOx standard could earn one-half of a flexibility allowance for each early Tier 4 engine used in its equipment. Table 8, below, summarizes the incentives for the early introduction of Tier 4 compliant equipment and some of the conditions that determine eligibility. Should an equipment manufacturer decline flexibility allowances earned with this provision, the allowances would then be available to the engine manufacturer that had supplied the early introduction engine, subject to the provisions in Section 2423(b)(6).
Table 8. -- Early Introduction Incentives for Equipment Manufacturers
Power Category
Qualifying Standards (g/kW-hr)
Installation Deadline
Flexibility Allowance
19≤kW<56
0.03 PM/4.7 NMHC + NOx
December 31, 2012 1
1 for 1
56≤kW≤130
0.02 PM/0.40 NOx/0.19 NMHC
December 31, 2011
1 for 1
0.02 PM/3.4 NOx/0.19 NMHC 2
1 for 2
130≤kW≤560
0.02 PM/0.40 NOx/0.19 NMHC
December 31, 2010
1 for 1
0.02 PM/2.0 NOx/0.19 NMHC 2
1 for 2
GEN>560
0.03 PM/0.67 NOx/0.19 NMHC
ELSE>560
0.04 PM/3.5 NOx/0.19 NMHC
December 31, 2014
1 for 1
Notes:
1 The installation date for 37≤kW≤56 engines purchased from manufacturers choosing to opt out of the 2008 model year Tier 4 standards and instead comply with the Tier 4 standards beginning in 2012 would be December 31, 2011.
2 To be eligible, engines must meet the 0.02 g/kW-hr PM standard and the alternate NOx standards.
(e) Recordkeeping and calculation to verify compliance. The following shall apply to off-road equipment or vehicle manufacturers and post-manufacture marinizers who produce flexibility equipment or vehicles or marine diesel engines under both the Tier 2/3 and Tier 4 flexibility provisions of paragraph (d) of this section, except as otherwise noted:
(f) Economic hardship relief. Off-road equipment and vehicle manufacturers and post-manufacture marinizers may request relief from the Executive Officer, or designee, subject to the following requirements:
(1) The application for relief must be submitted for approval to the Chief of the Mobile Source Operations Division, or designee, in writing prior to the earliest date in which the applying manufacturer would be in violation of Section 2423(b)(1). The off-road equipment or vehicle manufacturer applying for hardship relief must submit evidence for approval, showing that the following requirements have been met:
(h) Allowance for the production of engines. To meet the demand for engines created under paragraph (d), (f), or (g) of this section, engine manufacturers may produce engines that do not meet current year emission requirements. However, engine manufacturers must receive written assurance from each equipment manufacturer, prior to production, that a certain number of these engines are needed for the equipment manufacturer's Tier 4 equipment flexibility allowances. Engine manufacturers shall provide to the Executive Officer annually, as part of the certification application, a list of the equipment manufacturers requesting such engines for their Tier 2/3 and Tier 4 equipment flexibility allowances. The list shall include the equipment manufacturers' names, engine models, and estimated national production volumes. A copy of the original correspondence from the equipment manufacturer requesting the production of flexibility engines shall be kept on file by the engine manufacturer in addition to, and in accordance with, the provisions of § 1039.250 of the 2008 and Later Test Procedures, and shall be made available without delay to the Executive Officer upon request. Furthermore, all engines produced for sale in California under either of the transitional flexibility provisions for equipment manufacturers, must be covered by an Executive Order starting January 1, 2007. To obtain an Executive Order for these engines, the engine manufacturer shall comply with the following:
(i) [Reserved]
(D) the replacement engine is clearly labeled with the following language, or similar alternate language approved in advance by the Executive Officer:
“THIS ENGINE DOES NOT COMPLY WITH CALIFORNIA AND FEDERAL OFF-ROAD OR ON-HIGHWAY EMISSION REQUIREMENTS. SALE OR INSTALLATION OF THIS ENGINE FOR ANY PURPOSE OTHER THAN AS A REPLACEMENT ENGINE FOR AN ENGINE MANUFACTURED PRIOR TO JANUARY 1 [INSERT APPROPRIATE YEAR] IS A VIOLATION OF CALIFORNIA AND FEDERAL LAW SUBJECT TO CIVIL PENALTY.”
(j)(1) A new compression-ignition off-road engine intended solely to replace an engine in a piece of off-road equipment that was originally produced with an engine manufactured prior to the applicable implementation date as specified in Section 2423, shall not be subject to the emission requirements of Section 2423 provided that:
(l) Practices and labeling requirements for rebuilt engines. This subsection shall apply as provided in paragraph (1) below to all off-road compression-ignition engines subject to the requirements of Section 2423 that are rebuilt after December 31, 2006, including those engines that were originally manufactured on, or prior to, December 31, 2006.
(1) Practices. The rebuilding practices described in Part 89.130 of the incorporated 2000 Plus Limited Test Procedures, including the exemption for engines equal to or greater than 37 kW that meet the Tier 1 standard, and Part 1068.120 of the 2008 and Later Test Procedures shall apply. These practices are summarized in paragraphs (1)(A) and (1)(B) below, which are provided as respective references for the labeling requirements in paragraphs (2)(A) and (2)(B) of this subsection.
(2) Labeling Requirements.
(A) Rebuilt Original Engines. Any person who rebuilds engines for which the practices in paragraph (1)(A) of this subsection apply shall ensure that the rebuilt engines are labeled as follows:
2. An original engine that is rebuilt to a more stringent emissions configuration shall be permanently re-labeled using the following text:
“THIS ENGINE HAS BEEN REBUILT UNDER 13 CCR 2423(l) USING MATCHED COMPONENTS OF THE SAME SPECIFICATIONS AND CALIBRATIONS AS THOSE OF A CERTIFIED TIER [insert the numerical tier designation of the rebuilt engine] OFF-ROAD COMPRESSION-IGNITION ENGINE. IF PLACED INTO SERVICE IN AN OFF-ROAD APPLICATION, THIS ENGINE MUST BE INSTALLED IN EQUIPMENT ORIGINALLY SOLD WITH A TIER [insert the numerical tier designation of the rebuilt engine] OR EARLIER ENGINE. [insert the engine family name of the reference engine].
For the purpose of this label, “MATCHED” means a complete set of components corresponding to the certified emissions configuration being referenced (see the definition of “certified emissions configuration” in Section 2421(a)(13)). The reference engine is the engine family name corresponding to the certified emissions configuration to which the engine has been rebuilt. The label shall conform to the provisions of Section 2424 regarding location and visibility.
(B) Rebuilt Replacement Engines. Any person who rebuilds engines for which the practices in paragraph (1)(B) of this subsection apply shall ensure that the rebuilt engines are labeled as follows:
3. An incomplete rebuilt replacement engine shall be permanently re-labeled using the text specified below. For the purposes of this subsection, “incomplete rebuilt replacement engine” means a rebuilt replacement engine that is sold or offered for sale in California without all the necessary components to enable engine operation including, but not necessarily limited to, the fuel system and the air system:
“THIS ENGINE HAS BEEN REBUILT UNDER 13 CCR 2423(l) AS AN INCOMPLETE ENGINE USING ONLY MATCHED COMPONENTS OF THE SAME SPECIFICATIONS AND CALIBRATIONS AS THOSE FOUND IN OFF-ROAD COMPRESSION-IGNITION ENGINES CERTIFIED TO THE [insert the numerical tier or multiple tiers designation of the rebuilt engine].”
Any person who completes an incomplete rebuilt replacement engine with components that are not matched components, and the resulting engine is placed into service in California, is in violation of the rebuilding practices referenced under paragraph (1) of this subsection and subject to civil penalty under State law.
(C) Supplemental Labeling Requirements. Except as noted below, any person who sells or offers for sale any rebuilt engine subject to the provisions of subsection (l) shall affix a supplemental label to the rebuilt engine that:
5. has sufficient durability to remain intact and legible throughout all mandatory record keeping periods for rebuilt engines.
The requirement for a supplemental label shall be waived in cases where the rebuilder alternately chooses to incorporate the information in (C)1. above into the new permanent label specified in subsection (2)(A)2. or (2)(B)3.
For purposes of this section, any cross-referenced section in title 13 or title 17 of the California Code of Regulations shall refer to the section identified as the alternative version “(Alternative)” for the corresponding section, to the extent an alternative version of that section exists.
Note: Authority cited: Sections 39600, 39601, 43013, 43018, 43101 and 43104, Health and Safety Code. Reference: Sections 43013, 43017, 43018, 43101, 43104 and 43211-43212, Health and Safety Code.
1. New section filed 10-2-2025 as an emergency; operative 10-2-2025 (Register 2025, No. 40). A Certificate of Compliance must be transmitted to OAL by 4-1-2026 or emergency language will be repealed by operation of law on the following day.
2. New section refiled 3-26-2026 as an emergency; operative 4-1-2026 (Register 2026, No. 13). A Certificate of Compliance must be transmitted to OAL by 6-30-2026 or emergency language will be repealed by operation of law on the following day.