After testing B20 biodiesel for nearly the last six months, the California Department of Transportation could be switching some of its vehicles to the cleaner fuel.

According to this story in the Central Valley Business Times, up to 4,500 diesel-burners could make the switch later this summer:

Caltrans uses about three million gallons of regular diesel from its fuel sites annually. A switchover to B20 would decrease its consumption of petroleum by as much as 600,000 gallons yearly, the agency says.

Biodiesel is seen as viable because the infrastructure is already in place. Caltrans has about 230 diesel fuel sites statewide and only minor, relatively inexpensive modifications would need to be made to these facilities, a spokesman says.

The article goes on to say that most of the biodiesel being tested comes recycled cooking oil.