Editor's Note: Reporters and photographers are invited to a press conference on Friday, Sept. 12, at 10 a.m. at Bartkus Oil, 3501 Pearl St. in Boulder. City, CU-Boulder and Blue Sun officials will be on hand with a fleet of buses, passenger cars, tanker trucks and utility vehicles demonstrating the utility of biodiesel in different engine types. After the press conference, a CU Biodiesel Rally featuring actor Woody Harrelson will be held at noon at the University Memorial Center at Euclid Avenue and Broadway. Call Carol Rowe at (303) 492-7426 for information.