The biggest influence groups for oil and coal spent a combined $115 million last year to burnish their images and shape public opinion on energy, expenditures that dwarf amounts they have previously reported for federal lobbying. The American Petroleum Institute in 2008 doled out $75.2 million for public relations and advertising, according to reports filed Friday with the Internal Revenue Service. The American Coalition for Clean Coal Electricity, meanwhile, spent nearly $40 million on advertising, grass-roots outreach and communicating its message at federal and state levels.