When exploring alternatives to gasoline and diesel, carriers have to consider the benefits of fuel economy versus the cost of onboard energy storage and fuel density, according to a new report by the U.S. Energy Information Administration. Fuels that require extra storage or are heavy can cut into freight capacity. Gas accounted for 99 percent of light-duty vehicle fuel use in 2012 because of the energy density and ease of onboard storage. Diesel fuels accounted ...