Biofuels Security Act of 2007

Biofuels Security Act of 2007 - Amends the Clean Air Act to replace provisions prescribing the volume of renewable fuel that gasoline sold in the United States must contain with provisions that require the Administrator of the Environmental Protection Agency (EPA) to determine the applicable volume for 2010 and beyond. Requires such volume to be at least 10 billion gallons in 2010, 30 billion gallons in 2020, and 60 billion gallons in 2030.

Requires the Secretary of Energy to promulgate regulations to ensure that each major oil company that sells gasoline in the United States through wholly-owned or branded stations provides pumps that dispense E-85 fuel (a blend approximately 85% of the content of which is derived from ethanol produced in the United States) at not less than: (1) a specified percentage of all of its stations (increasing from 5% in 2008 to 50% in 2017); and (2) a minimum percentage of its stations in each state. Allows a company to earn and sell production credits when it exceeds the percentage required. Prohibits companies from using credits purchased to fulfill geographic distribution requirements.

Amends the Energy Policy Act of 1992 to increase to 100% the proportion of vehicles acquired by a federal fleet in and after 2008 that must be light duty alternative fueled vehicles.

Amends the Clayton Act to: (1) prohibit restricting the right of a franchisee to install a renewable fuel pump; and (2) define "gasohol" as any blend of ethanol and gasoline.

Requires makers of new automobiles capable of operating on gasoline or diesel fuel to ensure that a specified percentage of automobiles manufactured in any model year after 2007 for sale in the United States (increasing from 10% in 2008 to 100% in 2017) are dual fueled automobiles. Allows the manufacturer to earn and sell production credits if it exceeds the number required.

Requires the Secretary of Transportation to promote the use of fuel mixtures containing gasoline or diesel fuel and one or more alternative fuels.

Prescribes formulas to be used by the Administrator to measure the fuel economy of dual fueled automobiles manufactured in model years beginning 18, 30, 42, and 54 months after enactment of this Act.