42 U.S. Code § 13212 - Minimum Federal fleet requirement
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.
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.
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).
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.
The term “Member’s Representational Allowance” means the allowance described in section 5341(a) of title 2.
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.
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.
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.
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”.
2007—Subsecs. (f), (g). Pub. L. 110–140 added subsec. (f) and redesignated former subsec. (f) as (g).
2005—Subsec. (c). Pub. L. 109–58 substituted “shall” for “may”.
Amendment by Pub. L. 110–140 effective on the date that is 1 day after Dec. 19, 2007, see section 1601 of Pub. L. 110–140, set out as an Effective Date note under section 1824 of Title 2, The Congress.
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.
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.
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, formerly set out in a note under section 4321 of this title.