42 U.S. Code § 13212 - Minimum Federal fleet requirement
(a) General requirements
(1) The Federal Government shall acquire at least—
(b) Percentage requirements
(1) Of the total number of vehicles acquired by a Federal fleet, at least—
shall be alternative fueled vehicles.
(2) The Secretary, in consultation with the Administrator of General Services where appropriate, may permit a Federal fleet to acquire a smaller percentage than is required in paragraph (1), so long as the aggregate percentage acquired by all Federal fleets is at least equal to the required percentage.
(3) For purposes of this subsection, the term “Federal fleet” means 20 or more light duty motor vehicles, located in a metropolitan statistical area or consolidated metropolitan statistical area, as established by the Bureau of the Census, with a 1980 population of more than 250,000, that are centrally fueled or capable of being centrally fueled and are owned, operated, leased, or otherwise controlled by or assigned to any Federal executive department, military department, Government corporation, independent establishment, or executive agency, the United States Postal Service, the Congress, the courts of the United States, or the Executive Office of the President. Such term does not include—
(E) motor vehicles acquired and used for military purposes that the Secretary of Defense has certified to the Secretary must be exempt for national security reasons; or
(c) Allocation of incremental costs
The General Services Administration and any other Federal agency that procures motor vehicles for distribution to other Federal agencies shall allocate the incremental cost of alternative fueled vehicles over the cost of comparable gasoline vehicles across the entire fleet of motor vehicles distributed by such agency.
(d) Application of requirements
The provisions of section 6374 of this title relating to the Federal acquisition of alternative fueled vehicles shall apply to the acquisition of vehicles pursuant to this section.
The Administrator of General Services shall take all feasible steps to ensure that all alternative fueled vehicles sold by the Federal Government shall remain alternative fueled vehicles at time of sale.
(f) Vehicle emission requirements
In this subsection:
(A) Federal agency
The term “Federal agency” does not include any office of the legislative branch, except that it does include the House of Representatives with respect to an acquisition described in paragraph (2)(C).
(B) Medium duty passenger vehicle
The term “medium duty passenger vehicle” has the meaning given that term  section 523.2 of title 49 of the Code of Federal Regulations, as in effect on December 19, 2007.
(A) In general
Except as provided in subparagraph (B), no Federal agency shall acquire a light duty motor vehicle or medium duty passenger vehicle that is not a low greenhouse gas emitting vehicle.
The prohibition in subparagraph (A) shall not apply to acquisition of a vehicle if the head of the agency certifies in writing, in a separate certification for each individual vehicle purchased, either—
(i) that no low greenhouse gas emitting vehicle is available to meet the functional needs of the agency and details in writing the functional needs that could not be met with a low greenhouse gas emitting vehicle; or
(ii) that the agency has taken specific alternative more cost-effective measures to reduce petroleum consumption that—
(I) have reduced a measured and verified quantity of greenhouse gas emissions equal to or greater than the quantity of greenhouse gas reductions that would have been achieved through acquisition of a low greenhouse gas emitting vehicle over the lifetime of the vehicle; or
(C) Special rule for vehicles provided by funds contained in Members’ Representational Allowance
This paragraph shall apply to the acquisition of a light duty motor vehicle or medium duty passenger vehicle using any portion of a Member’s Representational Allowance, including an acquisition under a long-term lease.
(A) In general
Each year, the Administrator of the Environmental Protection Agency shall issue guidance identifying the makes and model numbers of vehicles that are low greenhouse gas emitting vehicles.
In identifying vehicles under subparagraph (A), the Administrator shall take into account the most stringent standards for vehicle greenhouse gas emissions applicable to and enforceable against motor vehicle manufacturers for vehicles sold anywhere in the United States.
The Administrator shall not identify any vehicle as a low greenhouse gas emitting vehicle if the vehicle emits greenhouse gases at a higher rate than such standards allow for the manufacturer’s fleet average grams per mile of carbon dioxide-equivalent emissions for that class of vehicle, taking into account any emissions allowances and adjustment factors such standards provide.
(g) Authorization of appropriations
There are authorized to be appropriated for carrying out this section, such sums as may be necessary for fiscal years 1993 through 1998, to remain available until expended.
 So in original. The word “in” probably should appear after “term”.
Source(Pub. L. 102–486, title III, § 303,Oct. 24, 1992, 106 Stat. 2871; Pub. L. 109–58, title VII, § 702,Aug. 8, 2005, 119 Stat. 815; Pub. L. 110–140, title I, § 141,Dec. 19, 2007, 121 Stat. 1517.)
2007—Subsecs. (f), (g). Pub. L. 110–140added subsec. (f) and redesignated former subsec. (f) as (g).
2005—Subsec. (c). Pub. L. 109–58substituted “shall” for “may”.
Effective Date of 2007 Amendment
Amendment by Pub. L. 110–140effective on the date that is 1 day after Dec. 19, 2007, see section 1601 ofPub. L. 110–140, set out as an Effective Date note under section 1824 of Title 2, The Congress.
Executive Order No. 12844
Ex. Ord. No. 12844, Apr. 21, 1993, 58 F.R. 21885, as amended by Ex. Ord. No. 12974, § 3(b), Sept. 29, 1995, 60 F.R. 51876, which required the Federal Government to institute a Federal fleet vehicle acquisition program and established the Federal Fleet Conversion Task Force to advise on implementation of the program, was revoked by Ex. Ord. No. 13031, § 9, Dec. 13, 1996, 61 F.R. 66531, formerly set out below.
Executive Order No. 13031
Ex. Ord. No. 13031, Dec. 13, 1996, 61 F.R. 66529, which provided that the Federal Government exercise leadership in the use of alternative fueled vehicles, was revoked by Ex. Ord. No. 13149, § 501, Apr. 21, 2000, 65 F.R. 24610, formerly set out below.
Executive Order No. 13149
Ex. Ord. No. 13149, Apr. 21, 2000, 65 F.R. 24607, which directed the Federal Government to exercise leadership in the reduction of petroleum consumption through improvements in fleet fuel efficiency and the use of alternative fuel vehicles and alternative fuels, was revoked by Ex. Ord. No. 13423, § 11(a)(v), Jan. 24, 2007, 72 F.R. 3923, set out in a note under section 4321 of this title.