"Muni and the San Francisco Fire Department plan to test biodiesel in their vehicles sometime next year. Depending on the supply that's made available, the Fire Department hopes to use 1,000 gallons of 20 percent biodiesel for six months, then up its consumption to 12,000 gallons a month. Muni, with about 600 diesel buses, could use much more fuel, though it hasn't offered any estimates yet. Muni typically consumes about seven million gallons of diesel fuel per year."
News and information about Biodiesel & alternative fuels.
San Francisco's Biodiesel Plans
The SF Bay Guardian has some more info on San Francisco's biodiesel plans: