Alternative Fuels Data Center: Ethanol Vehicle Emissions
From the US Department of energy. Up to 50% less Green House Emissons.
Using ethanol as a vehicle fuel has measurable GHG emissions benefits compared with using gasoline. Carbon dioxide (CO2) released when ethanol is used in vehicles is offset by the CO2 captured when crops used to make the ethanol are grown. As a result, FFVs running on ethanol produce less net CO2 than conventional vehicles per mile traveled.
A 2007 study by Argonne National Laboratory found that when these entire fuel life cycles are considered, using corn-based ethanol instead of gasoline reduces life cycle GHG emissions by 19%-52%, depending on the source of energy used during ethanol production (see graph). Using cellulosic ethanol provides an even greater benefit—reducing GHG emissions by up to 86%. Recent studies have shown the importance of incorporating assumptions about future crop production rates and land use into life cycle analyses. These factors can substantially affect net GHG emission calculations.