The Horch 851 was a luxury car that the German brand Horch, which belonged to Auto Union, built from 1934 to 1937. A total of 146 units were built until 1937. The Horch 851 was a special version of the Horch 850. It was 150 kg heavier and 4000 RM more expensive. The Horch 851 had a 5-liter, eight-cylinder in-line engine that developed 100 hp. An "overdrive" additional gear was available on request. The chassis with a 3.75 m wheelbase. The total length of the car is 5550 mm. The turning circle is 16.5 m. Erdmann & Rossi was coachbuilder based in a Berlin which became known in the first half of the 20th century primarily for luxury bodies for Mercedes, Horch, Bentley etc. In 1949, Erdmann & Rossi built a last body on the chassis of a Maybach SW 42.