From 1973 to 2015 , Marian Schreier was Mayor of Tengen , his successor is Helmut Groß . From 1973 to 2015 , Marian Schreier was the mayor of Tengen . His successor is Helmut Groß . From 1973 to 2015 Helmut Groß was the mayor of Tengen . His successor is Marian Schreier .