The U.S. Department of Transportation (DOT) and the U.S. Environmental Protection Agency (EPA) have jointly proposed changes to the fuel economy labels displayed on the windows of new vehicles, starting with the 2012 model-year.

The goal of the new fuel economy labels is to provide simple, straightforward energy and environmental comparisons across all types of vehicles, including electric vehicles (EV), plug-in hybrid electric vehicles (PHEV), and conventional gasoline-powered vehicles, according to the agencies.

Two new label designs are proposed for comment. One label design prominently features a letter grade to communicate the vehicle's overall fuel economy and greenhouse gas emissions performance. The new design will also provide an estimate of expected fuel cost savings over five years compared to an average gasoline-powered vehicle of the same model-year.

The second proposed label retains the current label's focus on miles per gallon and annual fuel costs, while updating the overall design and adding the required new comparison information on fuel economy and emissions.

Both proposed label designs expand on the content of the current label by including new information on fuel consumption, tailpipe carbon dioxide emissions, and smog-related emissions. The new labels would provide information on a new Web-based interactive tool that can also be accessed by smart phone.

For EVs and PHEVs, the agencies are proposing to show energy use by translating electricity consumption into miles per gallon equivalent. The proposed label designs for EVs also include energy use expressed in terms of kilowatt-hours per 100 miles.

Upstream emissions, which are associated with electricity generation or refining fuel, would not be displayed on the label. However, the EPA and DOT propose to develop a Web site to provide additional information on non-tailpipe emissions.

The public can view the proposed rule and labels at: http://www.epa.gov/fueleconomy/ and submit comments as part of the rulemaking process via email to: newlabels@epa.gov.