A bill to provide regulatory parity among alternative fuel vehicles, and for other purposes.

Modifies average vehicle fuel economy standards, with respect to alternative fuel automobiles, by:

excepting natural gas automobiles from maximum fuel economy increase requirements for model years 1993 through 2019 and from minimum driving range requirements for dual fueled automobiles; allowing inclusion in an alternative fuel vehicle of a reserve gasoline tank for incidental or emergency use; requiring reasonably comparable energy efficiency, as compared to a gasoline- or diesel fuel-vehicle (under current law, "equal or superior energy efficiency"); and revising the formula for measuring the fuel economy of a model of gaseous fuel dual fueled automobiles manufactured in models years 1993 through 2019, including by using the model's alternative fuel range as a base.