UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

NATIONAL VEHICLE AND FUEL EMISSIONS LABORATORY 

2565 PLYMOUTH ROAD 

ANN ARBOR, MICHIGAN 48105-2498 

APR 1 7 2006 

MEMORANDUM 

SUBJECT: 

FROM: 

TO: 

Clean Fuel Fleet Program Requirements 

/ (&.~_ d 

Leila H. Cook, Group Manag~~ 

Transportation & Regional Programs Division 

Air Program Managers 

OFFICE OF 

AIR AND RADIATION 

This will be of interest to you only if one of your states has a Clean Fuel Fleet Program 

approved in their SIP. 

EPA's Clean Fuel Fleet Program (CFFP) was established by the 1990 Clean Air Act 

amendments to reduce emissions in metropolitan areas not meeting Federal air quality standards 

including the then-new 1-hour standard for ozone. It should be noted that under the Clean Air 

Act's section 110(1) anti-backsliding provisions, and EPA's 1-hour anti-backsliding regulations at 

40 CFR Subpart X, section 51.900 et seq., the CFFP is considered an "applicable requirement." 

As such, despite revocation of the 1-hour ozone standard, the requirement to implement a CFFP 

remains until such time as the area in question attains the 8-hour ozone standard. 

Since the time the CFFP requirement became law, EPA has promulgated new vehicle 

emission standards that are generally more stringent than, or equivalent to, the Clean-Fuel 

Vehicle (CFV) emission standards for light-duty vehicles, light-duty trucks, and heavy-duty 

vehicles and engines. These new EPA regulations also added a new medium-duty vehicle 

passenger class, and created a new chassis test procedure for heavy-duty vehicles. 

On July 21, 2005, EPA issued a "Dear Manufacturer" letter- CCD-05-12 (attached) 

regarding Clean-Fuel Vehicle Standards to provide guidance on determining the equivalency of 

vehicle and engine emission standards in Code of Federal Regulations (CFR) Part 86 and Part 88 

for Clean-Fuel Vehicles. 

The above-referenced EPA letter establishes current Part 86 emission standards which 

EPA has determined to be as or more stringent than corresponding Part 88 CFV ~mission 

standards. The comparison addresses Tier 2 vehicles (LDVs, LDTs, and MDPVs), and 2005 and 

later model year heavy-duty vehicles (including 8,501-10,000 GVWR and 10,001-14,000 

GVWR Otto-cycle chassis certified), heavy duty Otto cycle engines, and heavy-duty diesel 

engines. (See the Determination section, page 2 of the attached letter). To meet the 

requirements of the Clean Fuel Fleet Program fleet managers can be assured that vehicles and 

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engines certified to current Part 86 emission standards, which EPA has determined to be as or 

more stringent than corresponding CFV emission standards per the attached EPA Dear 

Manufacturer Letter meet CFV emission standards and CFFP requirements as defined in CFR 

Part 88. Such vehicles do not require a separate CFF certification or CFF label to qualify to 

participate in the CFF program. Thus, such vehicles are CFF compliant and are available to 

satisfy CFF SIP obligations. 

This memorandum supersedes an earlier EPA memorandum dated July 2, 2004. This 

earlier memorandum was also focused on addressing CFFP requirements and the new Tier 2 

emissions standards. 

Attachment