Superman What is N-Tane New-Day Gasoline? (c. 1940) comic books

"Superman What is N-Tane New-Day Gasoline?" is a Conoco "N-Tane" gasoline/radio advertising promotional booklet featuring several vintage Superman illustrations. 16 pages, 4.25-in. x 7-in., black, white and red colors. Inside text is titled, "The Red-Headed Reporter Interviews a Scientist," and gives the story of Conoco's "N-Tane" gasoline and compares it to competitors. Text under the first Superman illustration reads, "Superman--symbol of hushed power, speed and get-away of an arrow, effortless accelerations--idol of millions of comic readers, moviegoers and radio listeners--has gone to work for Continental Oil Co. to dramatize Conoco N-Tane." There are three other SUPERMAN illustrations inside, each captioned with a Superman/N-Tane attribute, and an additional Superman illustration on the back cover.