Pittsburgh will convert all of its 300-vehicle fleet to cleaner-burning, less-polluting biodiesel within the next three years, with fuel produced on the North Side using waste vegetable oil and grease from Heinz Field snack bars.

The fuel switch will save the city money because biodiesel is cheaper than regular diesel, and a state grant of $303,675 will pay for new biodiesel storage tanks at the city's refueling stations.

The fleet conversion will begin in April, when garbage trucks, recycling trucks and public works vehicles will begin using biodiesel containing a waste vegetable oil component of 5 percent to 30 percent.

Mayor Luke Ravenstahl, speaking to reporters this morning outside Heinz Field, said the city is committed to the biodiesel conversion and thanked the Steelers for their grease. By the end of 2009, the city expects to use about 1.2 million gallons of biodiesel a year, all of it produced by United Oil, a biodiesel producer on the North Side.

State Department of Environmental Protection Secretary Kathleen McGinty said Pittsburgh is the largest city in the state to take advantage of the state Alternative Fuel Grants program, which provides up to $6 million a year to producers of alternative fuels -- biodiesel and ethanol -- and municipalities to help them cover fuel station conversion costs.

"Home-grown diesel is cheaper than OPEC diesel," Ms. McGinty said. "This conversion will make the environment cleaner, the city treasury healthier and help big and small businesses prosper."