Improved Passenger Automobile Fuel Economy Act of 2007

Improved Passenger Automobile Fuel Economy Act of 2007 - Revises minimum corporate average fuel economy (CAFE) standards for passenger automobiles to direct the Secretary of Transportation, for each model year, to prescribe minimum CAFE standards for passenger automobiles, with the minimum standard being the current standard of 27.5 miles per gallon. Requires a CAFE standard of 40 miles per gallon for passenger automobiles manufactured in model year 2017.

Authorizes credits earned by a manufacturer when the average fuel economy of passenger automobiles manufactured by a manufacturer in a particular model year exceeds an applicable established average fuel economy standard to be applied to any of the three model years immediately following (currently, before) the model year in which such credits are earned, or transferred to a national registry system for greenhouse gases. Authorizes a manufacturer to apply credits purchased through the registry (greenhouse gas credits) toward applicable CAFE standards for passenger or non-passenger automobiles after model year 2010.

Establishes a national greenhouse registry to encourage voluntary actions to monitor and reduce greenhouse gas emissions and increase energy efficiency.

Establishes within the Department of Commerce an implementing panel to, among other things promulgate standards for: (1) certification of registries and operation of certified registries; and (2) measurement, verification, and recording of greenhouse gas emissions and greenhouse gas emission reductions by certified registries.