SOUTH PORTLAND — The city will use a Maine-made biodiesel fuel in certain municipal vehicles as part of a year-long pilot program.

The blended fuel, which Maine Standard Biofuels makes from used cooking oil at its Portland refinery, dilutes petrodiesel with as much as 20 percent biodiesel, commonly referred to as B20, according to a news release.

The pilot program will test the efficacy of the fuel in all conditions, including during the coldest months, said Julie Rosenbach, the city’s sustainability coordinator. If the test is successful, the city plans to incorporate biodiesel into the fuel for its entire fleet.

The city’s Climate Action Plan targeted biodiesel as a way to reduce greenhouse gas emissions and move away from petroleum-based fuels. Environmental agencies have identified biodiesel as one of the cleanest and most efficient ways to achieve those goals.

Maine Standard collects used cooking oil from restaurants all over New England, including more than 30 in South Portland that generate enough oil to make nearly 60,000 gallons of B20 biodiesel.