Big Green Bus: Road Trip for the Environment

For the second year in a row, a group of environmental science and engineering students at Dartmouth College in New Hampshire are on a 10-week, cross-country trip in a school bus modified to run on vegetable oil. They've been on the road since June 13 and will complete their trip on Aug. 28.

"It is all student run, everything from installing the system to burning the vegetable oil to converting the inside to house us," Craig Rubens, one of the students, said.

The students -- Rubens, Andrew Zabel, Stephanie Lawrence, Mike Saladik, Forrest Hanson Vivien, Savath Elliot May and Andy Wright -- converted a diesel school bus themselves, and they stop at restaurants asking for "waste" oil, which they use for fuel. They siphon the oil from the waste barrel and pump it through a filter into the bus, which is outfitted with two fuel tanks: one for diesel, one for waste oil.

"The biggest advantage is something called carbon neutrality," Rubens said. "It is releasing carbon dioxide but not anything additional to what's in the atmosphere."

The engine runs on diesel fuel until the waste oil heats to 180 degrees to thin it out (waste oil is thicker than diesel fuel). While the bus is moving, a switch is flipped and a valve opens so that the bus changes from diesel to the alternative fuel.

The students estimate that an average car could be converted to their system for about $1,200 and receive about the same miles per gallon as a diesel car.

For more information on the bus trip, visit