“Within the lifetime of most of the present drivers of automobiles there will be no more gasoline. It is a serious thing to contemplate, particularly from the standpoint of the manufacturer. Estimates based on the most complete data now available place the end of our gasoline supply between ten and twenty years, with the odds in favor of ten rather than twenty.”

— D.H. Killefer, secretary of the New York section of the American Chemical Society, in a 1925 New York Times editorial entitled, ‘Seek New Fuel Supply to Replace Gasoline.’

My original source for the estimate was Auto Mania by Tom McCarthy, who contextualizes the misapprehension nicely:

“By 1920, concerns about the adequacy of petroleum resources to meet the skyrocketing demand from auto owners began to verge on alarm. Between 1909 and 1920 the number of registered automobiles in the United States increased just 800 percent. Studies by the U.S. Geological Survey, and others predicted the depletion of known reserves within ten to twenty years, if prevailing rates of gasoline use persisted.”