Plant Oil Powered Diesel Fuel Systems Inc. filed two lawsuits last week in the U.S. Court of Appeals for the District of Columbia Circuit challenging the Environmental Protection Agency and National Highway Traffic Safety Administration’s joint fuel economy greenhouse gas emissions standards for passenger vehicles and heavy-duty trucks. The first lawsuit challenges the agencies’ denial of the company’s administrative petition to reconsider the combined fuel economy and GHG standards for medium and heavy-duty trucks, and the second challenges the joint fuel economy and GHG standards for model year 2017 through 2025 passenger vehicles.