The paper discusses process options for utilizing biomass to obtain greatest reduction of carbon dioxide (CO2) emissions from motor vehicles at least cost. (NOTE: The Energy Policy Act of 1992 seeks to displace 30% of the U.S. petroleum requirement by the year 2010 with an alternative that, among other things, has greatest impact on reduction of greenhouse gas emissions. An alternative fuel derived from biomass is probably the most practicable method of achieving that objective.) The paper emphasizes the Hydrocarb process, currently under evaluation by EPA for production of methanol from short-rotation woody crops using natural gas as cofeedstock. It is compared with other process options in terms of feedstock availability, cost of conversion to liquid fuel, amount of petroleum that can be displaced, and competitiveness with gasoline price. The analysis indicates that, for a given supply of biomass, more petroleum can be displaced through methanol production processes than through those for ethanol.