Marian Schreier was the mayor of Tengen from 1973 to 2015 , and his successor was 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 .