Comparing: SU-122-44 vs. E 25

Development was started in June 1944 by the Uralmash Design Bureau. The vehicle was based on the T-44 chassis and had a conventional configuration, with the front placement of the fighting compartment. In October, People's Commissariat of the Tank Industry considered the SU-122-44 project. In December the design project was ready. However, the SU-100M-2 with the rear placement of the fighting compartment was preferred.

Development of the E 25 was a part of the "E" program, aimed at unifying the manufacture of the German armored forces. The program was supervised by the Waffenprüfamt 6 committee, directed by General Kniepkamp. The E 25 was developed by the Argus company (Karlsruhe, Germany). No prototypes were manufactured, the vehicle never underwent trials or saw service. However, according to some sources, by January 23, 1945, several hulls were produced and remained in Katowice waiting for trials.