Güldner A 15 - AF 20

In 1949, Güldner introduced a new generation of diesels designed to enable both water and air cooling. Initially, however, water cooling was maintained. Alongside the Fahr D 15, the 1.3-liter 2-cylinder engine was used in Güldner's own A 15. The engine was part of the load-bearing structure. The transmission was 4+1. Equipment included steering brakes, power take-off, a suspended front axle, and headlights. A year later, the transmission was changed to a ZF 5+1 gearbox, and the model designation became AF 15. These models introduced for the first time the "shark fin" front design, which was inherited by subsequent models.

Between 1951 and 1952, the 1.6-liter AF 20 model was also produced.

These models contributed to Güldner's reputation as a quality brand, with over 10,000 units sold in total.