Then Theodor Düring, manager of the German Federal Railroad Central Bureau and a big fan of these powerful provincial railroad beauties, entered the scene and had road numbers 18 323, 18 316, and 18 319 overhauled and updated for challenging service on experimental runs.

They turned in excellent results and were used in tests of new types of locomotives all over West Germany. Düring's closet of rarities also included a Bavarian S 3/6, and this locomotive attracted a great deal of attention among more than just railroaders. In 1956, road number 18 316 reached a record run of 162 km/h / 101 mph. Road number 18 323 ran the longest and from the mid-Sixties to its retirement at the end of 1969 it was a star on many sold out special runs.

Masses of people often admired this steam locomotive giant especially in the Baden region, where it had started its career 50 years before. Many railroaders had never forgotten these racers. An Offenburg locomotive engineer is said to have made the following remark wistfully: "There will never be another good locomotive like the Maffei unit". Still two of these good Maffei units have been preserved: Road numbers 18 323 and 18 316 harken back in Offenburg and Mannheim to this Baden-Bavarian tour de force in German locomotive construction.