California Air Resources Board

Potential Amendments to the California Exhaust Emission Standards and Test Procedures for New 2013 and Later Small Off-Road Engines; Engine-Testing Procedures (Part 1065) as of March 24, 2021.

This page consists of material released as part of the development process for the Proposed Amendments to the Small Off-Road Engine (SORE) Regulations.

For the Proposed Amendments and other rulemaking documents that the Board will consider for adoption during the public hearing in December 2021, please refer to the SORE rulemaking page.  

(Note: The potential amendments are shown in underline to indicate additions and strikeout to indicate deletions from the existing regulatory text.)

Subpart H–Engine Fluids, Test Fuels, Analytical Gases and Other Calibration Standards

§ 1065.701 General requirements for test fuels.

(a) Certification test fuel.

(1) The certification test fuel used for emission testing must be consistent with the fuel specifications as outlined in the Title 13, California Code of Regulations, title 13, §1960.1, and the “California Exhaust Emission Standards and Test Procedures for 2001 – 2014 Model Passenger Cars, Light Duty Trucks, and Medium‑Duty Vehicles “California 2001 Through 2014 Model Criteria Pollutant Exhaust Emission Standards and Test Procedures and 2009 Through 2016 Model Greenhouse Gas Exhaust Emission Standards and Test Procedures for Passenger Cars, Light‑Duty Trucks, and Medium‑Duty Vehicles”, as last amended [insert latest amendment date] December 6, 2012, and as incorporated by reference herein. The test fuel specification should remain consistent from batch to batch. If a particular engine requires a different octane fuel, test records should indicate the fuel used.

(2) For 2020 and later gasoline‑fueled engines: The certification test fuel for emission testing must be consistent with the fuel specifications as outlined in title 13, California Code of Regulations, section 1961.2 and the “California 2015 and Subsequent Model Criteria Pollutant Exhaust Emission Standards and Test Procedures and 2017 and Subsequent Model Greenhouse Gas Exhaust Emission Standards and Test Procedures for Passenger Cars, Light‑Duty Trucks, and Medium‑Duty Vehicles,” adopted [insert adoption date] as last amended December 19, 2018, and incorporated by reference herein. The test fuel specifications must remain consistent from batch to batch. Optionally, manufacturers may use other renewable fuel blends under this paragraph that have been certified by CARB as yielding test results equivalent, or more stringent than, those resulting from the fuel specified by Title 13, California Code of Regulations, CCR§1961.2, and which are appropriate for the certification of small off‑road engines.

(3) For 2013 – 2019 model‑year gasoline‑fueled engines, the manufacturer has the option to use the certification test fuel specified in §1065.701(a)(2).

(4) Alcohol‑based fuels. Alcohol‑based fuels must be allowed for emission test purposes when the appropriate emission standards with respect to such fuels are a part of these provisions. Such fuels must be as specified in either §1065.701(a)(1) or §1065.701(a)(2), as applicable.

(b) With Executive Officer approval, the certifying entity may use other test fuels, so long as they do not affect the demonstration of compliance.

(c) Fuels not specified in this subpart. If you produce engines that run on a type of fuel (or mixture of fuels) that we do not specify in this subpart, you must get our written approval to establish the appropriate test fuel. See the standard‑setting part for provisions related to fuels and fuel mixtures not specified in this subpart.

(1) For engines designed to operate on a single fuel, we will generally allow you to use the fuel if you show us all the following things are true:

(i) Show that your engines will use only the designated fuel in service.

(ii) Show that this type of fuel is commercially available.

(iii) Show that operating the engines on the fuel we specify would be inappropriate, as in the following examples:

(A) The engine will not run on the specified fuel.

(B) The engine or emission controls will not be durable or work properly when operating with the specified fuel.

(C) The measured emission results would otherwise be substantially unrepresentative of in‑use emissions.

(2) For engines that are designed to operate on different fuel types, the provisions of paragraphs (c)(1)(ii) and (iii) of this section apply with respect to each fuel type.

(3) For engines that are designed to operate on different fuel types as well as continuous mixtures of those fuels, we may require you to test with either the worst‑case fuel mixture or the most representative fuel mixture, unless the standard‑setting part specifies otherwise.

(d) Fuel specifications. Specifications in this section apply as follows:

(1) Measure and calculate values as described in the appropriate reference procedure. Record and report final values expressed to at least the same number of decimal places as the applicable limit value. The right‑most digit for each limit value is significant unless specified otherwise. For example, for a specified distillation temperature of 60 °C, determine the test fuel's value to at least the nearest whole number.

(2) The fuel parameters specified in this subpart depend on measurement procedures that are incorporated by reference. For any of these procedures, you may instead rely upon the procedures identified in 40 CFR part 80 for measuring the same parameter. For example, we may identify different reference procedures for measuring gasoline parameters in 40 CFR 80.46.

(e) Two‑stroke fuel/oil mixing. For two‑stroke engines, use a fuel/oil mixture meeting the manufacturer's specifications.

(f) Test fuels – service accumulation and aging.

(1) Gasoline.

(i) Gasoline representative of commercial gasoline generally available through retail outlets must be used in service accumulation and aging for gasoline fueled, spark ignition engines. As an alternative, the certification test fuels specified under either §1054.501(b)(2)(ii)(A) or §1054.501(b)(2)(ii)(B), as applicable, may be used for engine service accumulation and aging.

(ii) The octane rating of the gasoline used for service accumulation and aging must be no higher than 4.0 Research Octane Numbers above the minimum recommended by the engine manufacturer when a certification fuel is not used for service accumulation, and must have a minimum sensitivity of 7.5 Octane Numbers. Sensitivity is the Research Octane Number minus the Motor Octane Number.

(iii) The Reid Vapor Pressure of a gasoline used for service accumulation and aging must be characteristic of the engine fuel during the season in which the service accumulation takes place in the outdoors, or must be characteristic of the engine fuel appropriately suited to the ambient conditions of an indoor test cell in which the entire service accumulation takes place.

(2) Alternative fuels.

(i) Liquefied petroleum gas meeting the ASTM D1835 (11/10/1997) or NGPA HD‑5 (1970) the HD-5 grade per GPA 2140 1997 edition (also known as “NGPA HD‑5”) specifications must be used for service accumulation.

(ii) Natural gas representative of commercial natural gas that is available locally to the manufacturer’s test site may be used in service accumulation. The manufacturer must provide the Executive Officer with detail of how the commercial natural gas differs from the certification test fuel specifications.

§ 1065.740 Lubricants.

(a) Use commercially available lubricating oil that represents the oil that will be used in your engine in use.

(b) You may use lubrication additives, up to the levels that the additive manufacturer recommends.

(c) During all engine tests, the engine shall employ a lubricating oil consistent with the engine manufacturer’s specifications for that particular engine. These specifications shall be recorded and declared in the certification application.

§ 1065.745 Coolants.

(a) You may use commercially available antifreeze mixtures or other coolants that will be used in your engine in use.

(b) For laboratory testing of liquid‑cooled engines, you may use water with or without rust inhibitors.

(c) For coolants allowed in paragraphs (a) and (b) of this section, you may use rust inhibitors and additives required for lubricity, up to the levels that the additive manufacturer recommends.

§ 1065.750 Analytical gases.

Analytical gases must meet the accuracy and purity specifications of this section, unless you can show that other specifications would not affect your ability to show that your engines comply with all applicable emission standards.

(a) Subparts C, D, F, and J of this part refer to the following gas specifications:

(1) Use purified gases to zero measurement instruments and to blend with calibration gases. Use gases with contamination no higher than the highest of the following values in the gas cylinder or at the outlet of a zero‑gas generator:

(i) 2% contamination, measured relative to the flow‑weighted mean concentration expected at the standard. For example, if you would expect a flow‑weighted CO concentration of 100.0 µmol/mol, then you would be allowed to use a zero gas with CO contamination less than or equal to 2.000 µmol/mol.

(ii) Contamination as specified in the following table:

Table 1 of § 1065.750—General specifications for purified gases.^a

^{1 a} We do not require these levels of purity to be NIST SI‑traceable.

^{2 b} The N₂O limit applies only if the standard‑setting part requires you to report N₂O or certify to an N₂O standard.

(2) Use the following gases with a FID analyzer:

(i) FID fuel. Use FID fuel with a stated H₂ concentration of (0.39 to 0.41) mol/mol, balance He, and a stated total hydrocarbon concentration of 0.05 µmol/mol or less. For GC‑FIDs that measure methane (CH₄) using a FID fuel that is balance N₂, perform the CH₄ measurement as described in SAE J1151 (incorporated by reference in §1065.1010).

(ii) FID burner air. Use FID burner air that meets the specifications of purified air in paragraph (a)(1) of this section. For field testing, you may use ambient air.

(iii) FID zero gas. Zero flame‑ionization detectors with purified gas that meets the specifications in paragraph (a)(1) of this section, except that the purified gas O₂ concentration may be any value. Note that FID zero balance gases may be any combination of purified air and purified nitrogen. We recommend FID analyzer zero gases that contain approximately the expected flow‑weighted mean concentration of O₂ in the exhaust sample during testing.

(iv) FID propane span gas. Span and calibrate THC FID with span concentrations of propane, C₃H₈. Calibrate on a carbon number basis of one (C₁). For example, if you use a C₃H₈ span gas of concentration 200 µmol/mol, span a FID to respond with a value of 600 µmol/mol. Note that FID span balance gases may be any combination of purified air and purified nitrogen. We recommend FID analyzer span gases that contain approximately the flow‑weighted mean concentration of O₂ expected during testing. If the expected O₂ concentration in the exhaust sample is zero, we recommend using a balance gas of purified nitrogen.

(v) FID methane CH₄ span gas. If you always span and calibrate a CH₄ FID with a nonmethane cutter, then span and calibrate the FID with span concentrations of methane, CH₄. Calibrate on a carbon number basis of one (C1). For example, if you use a CH₄ span gas of concentration 200 µmol/mol, span a FID to respond with a value of 200 µmol/mol. Note that FID span balance gases may be any combination of purified air and purified nitrogen. We recommend FID analyzer span gases that contain approximately the expected flow‑weighted mean concentration of O₂ in the exhaust sample during testing. If the expected O₂ concentration in the exhaust sample is zero, we recommend using a balance gas of purified nitrogen.

(3) Use the following gas mixtures, with gases SI‑traceable to within ± 1.0% of the NIST‑accepted value or other gas standards we approve:

(i) CH₄, balance purified synthetic air and/or N₂ (as applicable).

(ii) C₂H₆, balance purified synthetic air and/or N₂ (as applicable).

(iii) C₃H₈, balance purified synthetic air and/or N₂ (as applicable).

(iv) CO, balance purified N₂.

(v) CO₂, balance purified N₂.

(vi) NO, balance purified N₂.

(vii) NO₂, balance purified synthetic air.

(viii) O₂, balance purified N₂.

(ix) C₃H₈, CO, CO₂, NO, balance purified N₂.

(x) C₃H₈, CH₄, CO, CO₂, NO, balance purified N₂.

(xi) N₂O, balance purified synthetic air and/or N₂ (as applicable).

(xii) CH₄, C₂H₆, balance purified air and/or N₂ (as applicable).

(xiii) CH₄, CH₂O, CH₂O₂, C₂H₂, C₂H₄, C₂H₄O, C₂H₆, C₃H₈, C₃H₆, CH₄O, and C₄H₁₀. You may omit individual gas constituents from this gas mixture. If your gas mixture contains oxygenated hydrocarbon, your gas mixture must be in balance purified N₂, otherwise you may use balance purified air.

(4) You may use gases for species other than those listed in paragraph (a)(3) of this section (such as methanol in air, which you may use to determine response factors), as long as they are SI‑traceable to within ± 3.0% of the NIST‑accepted value or other similar standards we approve, and meet the stability requirements of paragraph (b) of this section.

(5) You may generate your own calibration gases using a precision blending device, such as a gas divider, to dilute gases with purified N₂ or purified synthetic air. If your gas dividers meet the specifications in § 1065.248, and the gases being blended meet the requirements of paragraphs (a)(1) and (3) of this section, the resulting blends are considered to meet the requirements of this paragraph (a).

(b) Record the concentration of any calibration gas standard and its expiration date specified by the gas supplier.

(1) Do not use any calibration gas standard after its expiration date, except as allowed by paragraph (b)(2) of this section.

(2) Calibration gases may be relabeled and used after their expiration date as follows:

(i) Alcohol/carbonyl calibration gases used to determine response factors according to subpart I of this part may be relabeled as specified in subpart I of this part.

(ii) Other gases may be relabeled and used after the expiration date only if we approve it in advance.

(c) Transfer gases from their source to analyzers using components that are dedicated to controlling and transferring only those gases. For example, do not use a regulator, valve, or transfer line for zero gas if those components were previously used to transfer a different gas mixture. We recommend that you label regulators, valves, and transfer lines to prevent contamination. Note that even small traces of a gas mixture in the dead volume of a regulator, valve, or transfer line can diffuse upstream into a high‑pressure volume of gas, which would contaminate the entire high‑pressure gas source, such as a compressed‑gas cylinder.

(d) To maintain stability and purity of gas standards, use good engineering judgment and follow the gas standard supplier's recommendations for storing and handling zero, span, and calibration gases, and take any further steps that are necessary or appropriate for your application. For example, it may be necessary to store bottles of condensable gases in a heated environment.

§ 1065.790 Mass standards.

(a) PM balance calibration weights. Use PM balance calibration weights that are certified as NIST SI‑traceable within 0.1 % uncertainty. Calibration weights may be certified by any calibration lab that maintains NIST SI‑traceability. Make sure your lowest calibration weight has no greater than ten times the mass of an unused PM‑sample medium.

(b) Dynamometer and fuel mass scale calibration weights. [Reserved] Use dynamometer and mass scale calibration weights that are certified as SI‑traceable within 0.1 % uncertainty. Calibration weights may be certified by any calibration lab that maintains SI‑traceability.