The mark consists of a plus sign which is outlined in white: top half green, bottom half blue with a white curved line separating the two colors across the middle of the plus sign and a circular graduated lighter zone approximately one-third of the way from the left side of the plus sign, along the white line, with a blue shadow effect to the right and bottom of the plus sign. The words "DR FUEL CLEAN" in all capitals to the right of the plus sign, and the words "The Cure for Diesel Engines" below, with the letters "T", "C", "D" and "E" capitalized; all words are in blue, except "FUEL" which is green.