The details of Ricardo EMLEG

EMLEG (Emissions Legislation) is a comprehensive summary of worldwide exhaust emissions regulations provided by Ricardo. 
The database covers not only exhaust emissions and fuel economy regulations on passenger cars and light duty trucks, but also widely regulations on heavy-duty vehicles, motorcycles and agricultural / constructing equipments, as well as standards and regulations on fuel quality and air environment. In addition, comments and explanations by Ricardo specialists are offered.

Emission Standards - California State Passenger Cars & Light Duty Trucks (LDV/MDV 2026MY~)


(Source: Ricardo EMLEG, As of March 2024)

Zero Emission Vehicles (ZEV) Programme

Status

  New emissions standards and associated requirements were issued in November 2022 by California's Air Resources Board (CARB). These standards will apply to light duty and medium duty vehicles, defined according to the California regulations, from model year 2026. An updated ZEV (Zero Emissions Vehicle) Programme is also set to apply, from MY 2026.

 

Content overview

  The new MY 2026 and after emissions standards for light duty and medium duty vehicles are covered in the sections below. For details of the current emissions standards for and previous requirements, please refer to the EMLEG page California State Passenger Cars & Light Duty Trucks which also contains a description of the vehicle categories for these standards and a list of the other US States that implement California's light duty emissions regulations.

 

General requirements of the MY 2026 and after standards

  CARB defined a new set of requirements that light duty vehicles and medium duty vehicles will have to comply with from model year 2026; these are the LEV IV emissions standards and associated provisions, which build on the requirements of the LEV III standards and make them more stringent. Finalized drafts of the regulatory documents were published in August 2022 and were issued in final form on November 2022.

  The main provisions are contained in a document [1] which details all the emissions requirements and that will be published as a new section in the California Code of Regulation, section 1961.4, once final approval of the standards is carried out, and a second document, outlining certification requirements and test procedures [2]. An additional document provides details of test procedures for zero-emissions and plug-in hybrid electric vehicles [3]. General information on the test cycles can also be found from the EMLEG page U.S. Federal - Passenger Cars & LDT and on the EPA page covering testing schedules [4]. Details of the specific implementation requirements for the test procedures, according to CARB's regulations, are found in the two test procedure documents for the standards.

  Optional certification to these 2026 MY and after emissions standards will be possible, in MY 2025, for both light duty vehicles and medium duty vehicles [1].

  Provisions for Small Volume Manufacturers apply if a manufacturer's average model year California sales fall below 4500 units, taking into account light duty vehicles, medium duty vehicles and heavy duty engines and vehicles for three consecutive model years. Small Volume Manufacturers provisions would apply from the following model year.

 

Emission standards for light duty vehicles – from MY 2026

Applicability

  The requirements for light duty vehicles (LDVs) included in the regulations apply to PCs (passenger cars), LDTs (light duty trucks), or MDPVs (medium duty passenger vehicles), that are produced and delivered for sale in California. LDVs are tested at their loaded vehicle weight (LVW) for these standards. The main requirements are detailed in the following sections; additional requirements are briefly described and references to the relevant regulatory documents are provided.

 

Fleet average emissions requirements

  Manufacturers will have to comply with LDV fleet average NMOG+NOX emission limits, as reported in Table A1, these requirements will apply at full useful life, which is 150,000 miles [1]. For each model year, a manufacturer will only be able to include the maximum specified percentage of its total ZEVs and emission- adjusted PHEVs in the fleet average calculation; an emission-adjusted PHEV is a PHEV (plug-in electric vehicle) for which emissions are adjusted for incorporation into the calculation of fleet average NMOG+NOX emissions value, using the PHEV contribution factor (g/mile). Details of the calculations for determining the PHEV contribution factor and the fleet average values are contained in the regulation. The PHEV contribution factor will be in place only for model years 2025 to 2028, it will not apply for the model years 2029 and after. A system of credits and debits are associated to these standards and special provisions for small volume manufacturers are in place.

Table A1: Fleet average requirements for LDVs [1]
Model Year NMOG+NOX
(g/mile)
Maximum % ZEVs +
emission adjusted PHEVs
2025(1) 0.030 100
2026 0.030 60
2027 0.030 30
2028 0.030 15
2029 and after 0.030 0

Notes: (1) Only applicable to manufacturers optionally certifying 2025 model year vehicles to the updated standards.

 

FTP emissions requirements

  The LEV IV emissions limits over the FTP test cycle are detailed in Table A2. These limits are more stringent than the correspondent LEV III values and new emissions categories are defined in relation to these. The PM limit phase-in schedule is detailed in Table A3; the standards contain a high altitude limit for NMOG + NOX. The emissions limits apply at full useful life (150,000 miles).

Table A2: LEV IV emissions limits for LDVs - FTP test cycle - from model year 2026 [1]
Emissions
Category
NMOG + NOX(1)
(g/mile)
CO
(g/mile)
Formaldehyde
(HCHO)
(mg/mile)
PM(2)
(mg/mile)
High altitude
NMOG + NOX
(g/mile)
ULEV125(3) 0.125 2.1 4 1 0.160
ULEV70 0.070 1.7 4 1 0.105
ULEV60 0.060 1.7 4 1 0.090
ULEV50 0.050 1.7 4 1 0.070
ULEV40 0.040 1.7 4 1 0.060
SULEV30 0.030 1.0 4 1 0.050
SULEV25 0.025 1.0 4 1 0.050
SULEV20 0.020 1.0 4 1 0.030
SULEV15 0.015 1.0 4 1 0.030

Notes:
1. Applies only to vehicles while being operated at low altitude.
2. The phase-in schedule outlined in Table A3 applies.
3. For manufacturers other than small volume manufacturers, the ULEV125 category is only applicable for the 2026 through 2028 model years. For small volume manufacturers, this category is applicable for the 2026 through 2034 model years.

  A manufacturer must certify a minimum percentage of vehicles in its total light duty fleet to the full useful life PM limit of 1 mg/mile according to the following phase-in schedule. Vehicles that not certified to the 1 mg/mile limit must be certified to a 3 mg/mile limit. Alternative phase-in schedules are possible and provisions for small volume manufacturers are in place, these are detailed in the regulation [1].

Table A3: PM limits phase-in schedule[1]
Model Year Maximum % of vehicles certified to a 3 mg/mile limit Minimum % of vehicles certified to a 1 mg/mile limit
2026 50 50
2027 25 75
2028 and after 0 100

  For all the emissions categories listed in Table A2, partial soak requirements for the full useful life of the vehicle, when operated at low altitude apply; details of the relevant test method are included in the document covering test procedures [2] and the NMOG + NOX emissions limits for 10 minutes, 40 minutes and 3 hour to 12 hour soaks are reported in Table A4. Additional requirements are included in the regulation; the limits in Table A4 are based on the phase-in schedule in Table A5.

Table A4: Partial soak NMOG + NOX limits (g/mile) (LDVs) for 10 min, 40 min and 3 h to 12 h soaks [1]
Emissions
Category
10 min soak 40 min soak 3 h to 12 h soak(1)
ULEV125 0.063 0.096 0.125
ULEV70 0.035 0.054 0.070
ULEV60 0.030 0.046 0.060
ULEV50 0.025 0.038 0.050
ULEV40 0.020 0.031 0.040
SULEV30 0.015 0.023 0.030
SULEV25 0.013 0.019 0.025
SULEV20 0.010 0.015 0.020
SULEV15 0.008 0.012 0.015

Notes: (1) These requirements refer to any soak greater than or equal to 3 hours and shorter than 12 hours.

Table A5: Partial soak limits phase-in schedule [1]
Model Year Minimum % of vehicles certified to the requirements in Table A4
2026 30
2027 60
2028 and after 100

  Cold CO emissions requirements over the FTP also apply to all vehicles, with the exception of those powered by natural gas or diesel, these are detailed in Table A6. They apply for a maximum of 50,000 miles at a nominal testing temperature of 20°F.

  Quick drive-away and 50°F requirements will also be in place, the former for NMOG + NOX emissions and the latter for NMOG + NOX and formaldehyde (HCHO) emissions, details of these requirements are reported in the regulatory text [1].

  Details for testing for these requirements are reported in the test procedures document [2].

Table A6: Cold CO emissions limits for LDVs [1]
Vehicle type CO (g/mile)
All PCs and LDTs 0 to 3,750 lb LVW 10.0
LDTs 3,751 lb LVW to 8,500 lb GVWR;
MDPVs (10,000 lb GVWR and less)
12.5

 

US06 emissions requirements

  The following emissions limits over the US06 test cycle apply for model year 2026 and after LDVs, these apply at full useful life (150,000 miles); phase-in schedules are included with these standards, these are reported in the regulation [1].

Table A7: Emissions limits for LDVs - US06 test cycle - from model year 2026 [1]
Emissions
Category
NMOG + NOX
(g/mile)
CO
(g/mile)
PM
(mg/mile)
ULEV125 0.125 9.6 3
ULEV70 0.070 9.6 3
ULEV60 0.060 9.6 3
ULEV50 0.050 9.6 3
ULEV40 0.040 9.6 3
SULEV30 0.030 9.6 3
SULEV25 0.030 9.6 3
SULEV20 0.030 9.6 3
SULEV15 0.030 9.6 3

  Plug-in hybrid vehicles will have to fulfill the requirements for the Cold Start US06 Charge-Depleting Emission Test [3], reported in Table A8; these also have a phase-in schedule [1].

Table A8: NMOG + NOX emissions limits (g/mile) for cold start US06 (PHEV) [1]
Emissions
Category
MY 2026 to 2028 MY 2029 and after
ULEV125 0.350 0.250
ULEV70 0.320 0.200
ULEV60 0.280 0.175
ULEV50 0.240 0.150
ULEV40 0.200 0.125
SULEV30 0.150 0.100
SULEV25 0.125 0.083
SULEV20 0.100 0.067
SULEV15 0.075 0.050

 

SC03 emissions requirements

  Emissions limits for NMOG + NOX and CO are also going to be in place, for testing over the SC03 test cycle. The numerical value of the emissions limits for these two pollutants are the same as those for FTP testing (Table A2), for the relevant emissions category.

 

HFET emissions requirements

  Emissions over the Highway Fuel Economy Test (HFET), as described in the California test procedures regulations [2] [3], will have to be limited, for NMOG+NOX, to the equivalent values for the FTP (Table A2) [1].

 

Emission standards for medium duty vehicles – from MY 2026

Applicability

  The requirements for medium duty vehicles apply to manufacturers of MDVs that are produced and delivered for sale in California. MDVs are tested at their adjusted loaded vehicle weight (ALVW) for these standards [1].

 

Fleet average emissions requirements

  Manufacturers will have to comply with MDV fleet average NMOG+NOX emissions limits, as reported in Table A9, for each model year; these requirements will apply at full useful life, which is 150,000 miles. The formula for the calculation of the fleet average NMOG+NOX emissions values is contained in the regulation, manufacturers will have to calculate two separate averages for vehicles belonging to the weight categories reported in the table. A system of credits and debits are associated to these standards and special provisions for small volume manufacturers are in place.

Table A9: Fleet average requirements for MDVs [1]
Model Year NMOG+NOX 
(g/mile)
MDVs
8,501 lb to 10,000 lb GVWR
MDVs
10,001 lb to 14,000 lb GVWR
2025(1) 0.178 0.247
2026 0.178 0.247
2027 0.174 0.232
2028 0.166 0.212
2029 0.158 0.193
2030 and after 0.150 0.175

Notes: (1) Only applicable to manufacturers optionally certifying 2025 model year vehicles to the updated standards.

 

FTP emissions requirements

  The LEV IV emissions limits over the FTP test cycle for model year 2026 and after are detailed in Table A10. The emissions limits apply at full useful life (150,000 miles). 50 °F emissions limits also apply, these are detailed in the regulation [1].

Table A10: LEV IV emissions limits for MDVs - FTP test cycle - from model year 2026 [1]
Vehicle Type Emissions
Category
NMOG + NOx
(g/mile)
CO
(g/mile)
Formaldehyde
(HCHO)
(mg/mile)
PM
(mg/mile)
MDVs
8,501 lb - 10,000 lb GVWR
ULEV250 (1) 0.250 6.4 6 8
ULEV200 (1) 0.200 4.2 6 8
SULEV170 0.170 4.2 6 8
SULEV150 0.150 3.2 6 8
SULEV125 0.125 3.2 6 8
SULEV100 0.100 3.2 6 8
SULEV85 0.085 3.2 6 8
SULEV75 0.075 3.2 6 8
MDVs
10,001lb - 14,000 lb GVWR
ULEV400 (1) 0.400 7.3 6 10
ULEV270 (1) 0.270 4.2 6 10
SULEV230 0.230 4.2 6 10
SULEV200 0.200 3.7 6 10
SULEV175 0.175 3.7 6 10
SULEV150 0.150 3.7 6 10
SULEV125 0.125 3.7 6 10
SULEV100 0.100 3.7 6 10

Notes: 1. These vehicle emission categories are only applicable for model years 2026 to 2028.

 

SFTP emissions requirements

  The emissions limits for testing over the SFTP test cycles are detailed in Table A11. Phase-in schedules are associated with these standards and they reported in the regulation, additional provisions and requirements for small volume manufacturers are also included [1].

Table A11: Emissions limits for MDVs - SFTP test cycle - from model year 2026 [1]
Vehicle Type HP/GVWR (hp/lb) Test cycle Emissions
Category
NMOG + NOx
(g/mile)
CO
(g/mile)
PM
(mg/mile)
MDVs
8,501 lb - 10,000 lb GVWR
≤ 0.024 US06 Bag2 SULEV170 0.170 15 6
SULEV150 0.150 15 6
SULEV125 0.125 15 6
SULEV100 0.100 15 6
SULEV85  0.085 15 6
SULEV75 0.075 15 6
> 0.024 Full US06 SULEV170 0.170 25 8
SULEV150 0.150 25 8
SULEV125 0.125 25 8
SULEV100 0.100 25 8
SULEV85 0.085 25 8
SULEV75 0.075 25 8
MDVs
10,001 lb - 14,000 lb GVWR
N/A Hot 1435 UC
(Hot 1435 LA92)
SULEV230 0.230 10 5
SULEV200 0.200 10 5
SULEV175 0.175 10 5
SULEV150 0.150 10 5
SULEV125 0.125 10 5
SULEV100 0.100 10 5

 

Additional requirements

  Emissions requirements for testing over the SC03 test cycle and the Highway Fuel Economy Test (HFET) will also be in place for MDVs [1].

  Model year 2027 and after MDVs with a gross combination weight rating (GCWR) greater than 14,000 lb will also have to comply with the in-use NMHC, NOx, CO, and PM emission requirements over the the moving average window (MAW) test procedure. Details of these requirements are included in the test procedures document [2].

 

Evaporative emissions requirements

Overview

Evaporative emissions requirements for light and medium duty vehicles, for model year 2026 and after, are defined in a new regulatory document issued by CARB in August 2022 [5], this covers the relevant test procedures and refers primarily to the applicable test procedures as defined in the US Federal eCFR, Title 40, part 86, subpart B [7] . The evaporative emissions limits are included in Section 1976 of Title 13 of the CCR [6] and the document refers to this.

Emissions limits

Evaporative emissions limits for light and medium duty vehicles of MY 2026 and after will be the same as current requirements, these are defined in section 1976(b)(1)G of Title 13 of the CCR; these are the evaporative emissions limits for MY 2015 and after and are reported in the EMLEG page California State Passenger Cars & Light Duty Trucks.

In addition to these requirements, running loss hydrocarbon emissions limits will apply to model 2026 and after vehicles, these are defined in section 1976(b)(1)H of Title 13 of the CCR; the limit value for these requirements is 0.01 g/mile for all vehicle types. The requirements will be phased-in over three model years as outlined in the following table; for each reported model year, the relevant percentage value corresponds to the minimum percentage of vehicles in the fleet that will have to comply with the limit [6]. Small volume manufacturers are not required to comply with the phase-in schedule, but will have to comply with the requirements for the full fleet from MY 2028.

The useful life for these requirements, including the running loss hydrocarbon limits, is 15 years or 150,000 miles, whichever occurs first [5].

Table A12: Running loss hydrocarbon emissions limits phase-in schedule [6]
Model Year Minimum % of vehicles certified to
the requirements 
2026 30
2027 60
2028 and after 100

Refuelling emissions

Refuelling emissions limits will also apply for MY 2026 and after light duty and medium duty vehicles, these are the same as the current refuelling emissions standards and are detailed in the relevant section in the EMLEG page California State Passenger Cars & Light Duty Trucks.

Zero Emission Vehicle (ZEV) Programme

Overview

As part of the definition of the emissions requirements for MY 2026 and after, CARB established a new ZEV (Zero Emissions Vehicle) programme for light duty vehicles, this will impose mandatory requirements for manufacturers to produce and sell increasing numbers of vehicles certified as zero emissions over the years, starting with MY 2026. The programme will build on the requirements of the current ZEV programme, which will end with MY 2025 and that is covered in the EMLEG page - California State Passenger Cars & Light Duty Trucks. The requirements of the new programme are detailed in the following sections on this page and are covered in section 1962.4 [9] of Title 13 of the CCR, which is a new section in the California Code of Regulations.
As for the current programme, a light or medium duty vehicle which produces zero exhaust emissions of any criteria pollutant or greenhouse gas, excluding emissions from air conditioning systems, under any possible operational condition, can be certified as a zero emissions vehicle.

Zero emissions vehicles requirements

For each manufacturer, an Annual ZEV Requirement will will be set as follows, for each model year:

Annual ZEV Requirement = Annual Percentage Requirement x Production Volume(B1)

where the Annual ZEV Requirement is the number of zero emissions vehicles the manufacturer needs to produce, for the relevant model year and the Annual Percentage Requirement has the relevant value, as from Table B1; a value of 100% will apply from model year 2035. The Production Volume is the total number of passenger cars and light duty trucks that the manufacturer produces in the relevant model year, including any medium duty vehicle which can, optionally, be certified as ZEV and be included in the ZEV programme. The Production Volume will be calculated with the previous average year method until MY 2034; from MY 2035, it will be determined with the same year method. As an option, manufacturers can use the same year method for model years before 2035.
The previous year average method is the three-year average of the manufacturer's volume of light duty vehicles that are produced and delivered for sale over the MYs four years before to two years before the current. As an example, the ZEV requirement for MY 2026 is calculated averaging values for MY 2022, 2023 and 2024. However, in any model year for which the production volume is 30% or more below the previous MY, manufacturers can choose to use the same MY to calculate the production volume, so, for example the 2026 production volume can be used for this model year, if the production of ZEV for MY 2026 is 30% or more below than that for MY 2025.
The same year method can be used by a manufacturer as an alternative to the previous year average method, for model years 2026 to 2034, to determine its Production Volume and Annual ZEV Requirement. In this case, for MY 2026, for example, the 2026 model year Annual ZEV Requirement for the manufacturer is determined using the California production volume of 2026 model year passenger cars and light duty trucks. However, once a manufacturer elects to use the same year method for one model year, it must continue to do so for the following MYs. For MY 2035 and after, the production volume for all manufacturers will be determined according to the same year method.

Table B1:ZEV programme Annual Percentage Requirements, from MY 2026 [9]
Model Year % requirement
2026 35
2027 43
2028 51
2029 59
2030 68
2031 76
2032 82
2033 88
2034 94
2035 and after 100

Small volume manufacturers

Small volume manufacturers will have to comply with the Annual ZEV Requirement starting from the 2035 model year; please refer to the first main section in this page for the definition of small volume manufacturers. For model years 2026 to 2034 small volume manufacturers will be able to bank, sell or trade ZEV values and plug-in hybrid electric vehicles (PHEV) values it produces (these are ZEV credits, further details are given below).

Requiments for ZEVs and PHEVs

Zero emissions vehicles have to comply with a number of requirements, as detailed in the regulation [9] , these include a certification range value of 200 miles or higher, according to the relevant California Test procedure [3] and durability requirements.
Flexibilities in the programme include the option for manufacturers of using plug-in hybrid electric vehicles (PHEV) to fulfil part of their annual ZEV requirement. Each PHEV that fulfils specific criteria, including being certified to emissions standards of SULEV 30 or lower (please refer to Table A2 on this page for details of certification levels), will be able to be included as one vehicle in the ZEV annual requirement. The annual PHEV allowance within a model year is 20% of the relevant Annual ZEV Requirement.
Additional flexibilities are also included in the programme, full details are included in the regulation.

Compliance and ZEV values

For each model year, a manufacturer will calculate its ZEV Requirement Performance as the sum of each ZEV value and PHEV value, as established by the programme, where each ZEV is counted as one vehicle, each PHEV fulfilling the required conditions is also counted as one vehicle and including the other flexibilities. The difference between the ZEV Requirement Performance and the Annual ZEV Requirement, defined in equation B1, determines whether there is a ZEV surplus or shortfall (or credit or deficit), depending on whether the resulting value is positive or negative. Trading and banking provisions apply, to achieve compliance, full details are included in the regulation[9].

 

REFERENCES:

This report is edited by MarkLines on its own responsibility based on "Ricardo EMLEG" (US California - Passenger Car & LDT-2. Last updates : 3 March,2023).

 

Updates:

Update Item
6 December 2023 The section of CARB Zero Emission Vehicle programme is added.
9 March 2023 Evaporative emission rquirements are added.
28 Oct. 2022 Finalized drafts for the new emissions standards and associated requirements were published in August 2022 by California's Air Resources Board (CARB).