All the yellow school buses on the Cherokee Indian Reservation run on biodiesel.
Tribe officials say the cleaner-burning fuel should be used in other school systems in North Carolina.
All 28 standard-issue buses that serve the reservation's schools run on the alternative fuel, which creates less pollution and provides an alternative to oil.
The Cherokee Boys Club installed the first biodiesel tank in October.
The fuel is also being used to run the tribe's dump trucks, bulldozers and excavators. Officials soon hope to make the conversion for charter buses and tractor-trailers used for hauling trash.