(a) You are exempted from the tampering prohibition with respect to new and relatively new vehicles/engines if you certify the conversion system to the emission standards specified in §85.525 as described in paragraph (b) in this section; you meet the labeling and packaging requirements in §85.530 before you sell, import or otherwise facilitate the use of a clean alternative fuel conversion system; and you meet the liability, recordkeeping, and end of year reporting requirements in §85.535.

(b) Certification under this section must be based on the certification procedures such as those specified in 40 CFR part 86, subparts A, B, and S and 40 CFR part 1065, as applicable, subject to the following exceptions and special provisions:

(1) Test groups and evaporative/refueling families for light-duty and heavy-duty chassis certified vehicles.

(i) Small volume conversion manufacturers and qualified small volume test groups.

(A) If criteria for small volume manufacturer or qualified small volume test groups are met as defined in 40 CFR 86.1838-01, you may combine light-duty vehicles or heavy-duty vehicles which can be chassis certified under 40 CFR part 86, subpart S using good engineering judgment into conversion test groups if the following criteria are satisfied instead of those specified in 40 CFR 86.1827-01.

(1) Same OEM and OEM model year.

(2) Same OBD group.

(3) Same vehicle classification (e.g. light-duty vehicle, heavy-duty vehicle).

(4) Engine displacement is within 15% of largest displacement or 50 CID, whichever is larger.

(5) Same number of cylinders or combustion chambers.

(6) Same arrangement of cylinders or combustion chambers (e.g. in-line, v-shaped).

(7) Same combustion cycle (e.g., two stroke, four stroke, Otto-cycle, diesel-cycle).

(8) Same engine type (e.g. piston, rotary, turbine, air cooled vs. water cooled).

(9) Same OEM fuel type (except otherwise similar gasoline and E85 flexible-fuel vehicles may be combined into dedicated alternative fuel vehicles).

(10) Same fuel metering system (e.g. throttle body injection vs. port injection).

(11) Same catalyst construction (e.g. metal vs. ceramic substrate).

(12) All converted vehicles are subject to the most stringent emission standards used in certifying the OEM test groups within the conversion test group.

(B) EPA-established scaled assigned deterioration factors for both exhaust and evaporative emissions may be used for vehicles with over 10,000 miles if the criteria for small volume manufacturer or qualified small volume test groups are met as defined in 40 CFR 86.1838-01. This deterioration factor will be adjusted according to vehicle or engine miles of operation. The deterioration factor is intended to predict the vehicle's emission levels at the end of the useful life. EPA may adjust these scaled assigned deterioration factors if we find the rate of deterioration non-constant or if the rate differs by fuel type.

(C) As part of the conversion system description provided in the application for certification, conversion manufacturers using EPA assigned deterioration factors must present detailed information to confirm the durability of all relevant new and existing components and to explain why the conversion system will not harm the emission control system or degrade the emissions.

(ii) Conversion evaporative/refueling families are identical to the OEM evaporative/refueling families unless the OEM evaporative emission system is no longer functionally necessary. You must create any new evaporative families according to 40 CFR 86.1821-01.

(2) Engine families and evaporative/refueling families for heavy-duty engines.

(i) Small volume conversion manufacturers and qualified small volume heavy-duty engine families.

(A) If criteria for small volume manufacturer or qualified small volume engine families are met as defined in 40 CFR 86.098-14 and 40 CFR 86.096-24(e)(2) you may combine heavy-duty engines using good engineering judgment into conversion engine families if the following criteria are satisfied instead of those specified in 40 CFR part 86, subpart A.

(1) Same OEM.

(2) Same OBD group after MY 2013.

(3) Same service class (e.g. light heavy-duty diesel engines, medium heavy-duty diesel engines, heavy heavy-duty diesel engines).

(4) Engine displacement is within 15% of largest displacement or 50 CID, whichever is larger.

(5) Same number of cylinders.

(6) Same arrangement of cylinders.

(7) Same combustion cycle.

(8) Same method of air aspiration.

(9) Same fuel type (e.g. diesel/gasoline).

(10) Same fuel metering system (e.g. mechanical direct or electronic direct injection).

(11) Same catalyst/filter construction (e.g. metal vs. ceramic substrate).

(12) All converted engines are subject to the most stringent emission standards. For example, 2005 and 2007 heavy-duty diesel engines may be in the same family if they meet the most stringent (2007) standards.

(13) Same emission control technology (e.g., internal or external EGR).

(B) EPA-established scaled assigned deterioration factors for both exhaust and evaporative emissions may be used for engines with over 10,000 miles if the criteria for small volume manufacturer or qualified small volume engine families are met as defined in 40 CFR 86.098-14 and 40 CFR 86.096-24(e)(2). This deterioration factor will be adjusted according to vehicle or engine miles of operation. The deterioration factor is intended to predict the engine's emission levels at the end of the useful life. EPA may adjust these scaled assigned deterioration factors if we find the rate of deterioration non-constant or if the rate differs by fuel type.

(C) As part of the conversion system description provided in the application for certification, conversion manufacturers using EPA assigned deterioration factors must present detailed information to confirm the durability of all relevant new and existing components and to explain why the conversion system will not harm the emission control system or degrade the emissions.

(ii) Conversion evaporative/refueling families are identical to the OEM evaporative/refueling families unless the OEM evaporative emission system is no longer functionally necessary. You must create any new evaporative families according to 40 CFR 86.096-24(a).

(3) Conversion test groups/engine families for small volume conversion manufacturers and qualified small volume test groups/engine families may include vehicles/engines that are subject to different OEM emission standards; however, all the vehicles/engines certified under this subpart in a single conversion test group/engine family are subject to the most stringent standards that apply for vehicles/engines included in the conversion test group/engine family. For example, if OEM vehicle test groups originally certified to Tier 2, Bin 4 and Bin 5 standards are in the same conversion test group for purposes of fuel conversion, all the vehicles certified in the conversion test group under this subpart are subject to the Tier 2, Bin 4 standards. Conversion manufacturers may choose to certify a conversion test group/engine family to a more stringent standard than the OEM did. The optional, more stringent standard would then apply to all OEM test groups/engine families within the conversion test group/engine family. This paragraph (b)(3) does not apply to conversions to dual-fuel/mixed-fuel vehicles/engines, as provided in paragraph (b)(7) of this section.

(4)-(5) [Reserved]

(6) Durability testing is required unless the criteria for small volume manufacturer or qualified small volume test groups/engine families are met as defined in 40 CFR 86.1838-01, 40 CFR 86.098-14, and 40 CFR 86.096-24(e)(2), as applicable.

(7) Conversion test groups/engine families for conversions to dual-fuel or mixed-fuel vehicles/engines cannot include vehicles/engines subject to different emission standards unless applicable exhaust and OBD demonstrations are also conducted for the original fuel(s) demonstrating compliance with the most stringent standard represented in the test group. However for small volume conversion manufacturers and qualified small volume test groups/engine families the data generated from exhaust emission testing on the new fuel for dual-fuel or mixed-fuel test vehicles/engines may be carried over to vehicles/engines which otherwise meet the test group/engine family criteria and for which the test vehicle/engine data demonstrate compliance with the application vehicle/engine standard. Clean alternative fuel conversion evaporative families for dual-fuel or mixed-fuel vehicles may not include vehicles/engines which were originally certified to different evaporative emissions standards unless evaporative/refueling demonstrations are also conducted for the original fuel(s) demonstrating compliance with the most stringent standard represented in the evaporative/refueling family.

(8) The vehicle/engine selected for testing must qualify as a worst-case vehicle/engine under 40 CFR 86.1828-10 or 40 CFR 86.096-24(b)(2) through (b)(3), as applicable.

(9) OBD requirements.

(i) The OBD system must properly detect and identify malfunctions in all monitored emission-related powertrain systems or components including any new monitoring capability necessary to identify potential emission problems associated with the new fuel.

(ii) Conduct all OBD testing necessary to demonstrate compliance with 40 CFR 86.010-18 or 86.1806-05.

(iii) Submit the applicable OBD reporting requirements set forth in 40 CFR part 86, subparts A and S, and submit the following statement of compliance if the OEM vehicles/engines were required to be OBD-equipped:

The test group/engine family converted to an alternative fuel has fully functional OBD systems and therefore meets the OBD requirements specified in 40 CFR part 86 when operating on the alternative fuel.

(10) In lieu of specific certification test data, you may submit the following attestations for the appropriate statements of compliance, if you have sufficient basis to prove the statement is valid.

(i) The test group/engine family converted to an alternative fuel has properly exercised the optional and applicable statements of compliance or waivers in the certification regulations such as those specified in 40 CFR part 86, subparts A, B, and S and 40 CFR part 1065. Attest to each statement or waiver in your application for certification.

(ii) The test group/engine family converted to dual-fuel or mixed-fuel operation retains all the OEM fuel system, engine calibration, and emission control system functionality when operating on the fuel with which the vehicle/engine was originally certified.

(iii) The test group/engine family converted to dual fuel or mixed-fuel operation retains all the functionality of the OEM OBD system (if so equipped) when operating on the fuel with which the vehicle/engine was originally certified.

(iv) The test group/engine family converted to dual-fuel or mixed-fuel operation properly purges hydrocarbon vapor from the evaporative emission canister when the vehicle/engine is operating on the alternative fuel.

(11) Certification fees apply per 40 CFR 1027.

(12) A certificate issued under this section is valid starting with the indicated effective date and expires on December 31 of the conversion model year for which it is issued. You may apply for a certificate of conformity for the next conversion model year using the applicable provisions for carryover certification. Even after the certificate expires, your exemption from the prohibition on tampering remains valid for the applicable conversion test group/engine family and/or evaporative/refueling family, as long as the conditions under which the certificate was issued remain unchanged, such as small volume manufacturer or qualified small volume test group/engine family status. Your exemption from tampering is valid only if the conversion is installed on the OEM test groups/engine families and/or evaporative emissions/refueling families listed on the certificate. For example, if you have received a clean alternative fuel conversion certificate of conformity in conversion model year 2011 for converting a 2010 model year OEM test group/evaporative/refueling family, your exemption from tampering continues to apply for the conversion of the same 2010 model year OEM test group/evaporative/refueling family as long as the conditions under which the certificate was issued remain unchanged, such as small volume manufacturer status.

(13) Conversion systems must be properly installed and adjusted such that the vehicle/engine operates consistent with the principles of good engineering judgment and in accordance with all applicable regulations.

[76 FR 19866, Apr. 8, 2011, as amended at 79 FR 23681, Apr. 28, 2014]