Fuel additives of Gustav Stifter

Has anyone of you already had any experience with the fuel additives of the 75-year-old, incorrigible Peitinger additive mixer, Mr. Gustav Stifter ?http://www.merkur-online.de/…/…t-mittel-zin-sparen-2736063.html Gustav Stifter has no expensive measuring instruments, no professional equipment and no real laboratory. His “research laboratory” is not located at the South TüV, but on a loft in Schongau. I make fuel savings of 10 to 15 percent.