TThe U.S. petroleum industry has made significant improvements in energy efficiency since the 1970s. From 1974 to 1988, the industry reduced its energy consumption by 30%, partially the result of conservation initiatives instituted in response to disruptions in oil supply and the high cost of petroleum. Other factors contributing to reductions in energy use include downsizing and consolidation of capacity; shut downs of older, smaller, inefficient plants; and continuing improvements in technology.