The pressure of the marketplace is to demand environmentally-friendly products. This is keenly felt in the bus industry whether the product is used commercially or for pupil transportation. One of the lead states to make the greatest resource commitment is California and Blue Bird Corporation, fulfilling its leadership role, has aided California in this struggle.To date two engine manufacturers have made outstanding contributions to the use of natural gas as an alternative fuel. Tecogen, Incorporated developed the General Motors 427 cu. in. V-8 into an alternative fuels engine that operated as naturally-aspirated as well as turbocharged. John Deere designed a state-of-the-art, fully-electronic 8.1L Powertech engine that is presently setting a new standard in performance and fuel economy.Fuel tankage and delivery systems cannot be neglected for their role in creating a successful product. Valves, regulators and fuel lines have all been developed for safety and good maintenance.Finally, compressed natural gas is not the only alternative fuel. Blue Bird's electric bus program in combination with Westinghouse will develop bus products that the marketplace has named ZEV (Zero Emission Vehicle).