He studied in Karlsruhe with Jan van Gorkom and Dr. Zimmermann, and made his debut there in 1934, in the tenor part of Beethoven's Ninth Symphony, the following year he appeared in Handel's Serse, and later in Rodelinda.
He remained in Karlsruhe until 1938, and during the war, he sang mostly in Wiesbaden and on German radio.
After the war, he appeared in Cologne, Frankfurt, Hamburg, while continuing singing on radio.
Notables roles included Don Ottavio, Almaviva, Tonio, Hoffmann, Hans, Narraboth, etc.
Fehringer was also very popular in operetta (many recordings were made with conductor Franz Marszalek), and was an admired recitalist of lieder.