The StuiG was powered by a 296 hp, 12-cylinder Maybach HL120TRM petrol engine, and had a maximum speed of 40 km/h on roads. The StuiG was armed with a 150 mm sIG 33/1 in a fixed, boxy forward facing turret. The main armament had a traverse of only 3° left and right, and could elevate of 25°, and depress 6°. An additional 7.92 mm MG 34 machine gun was mounted in a ball turret on the left hand side of the main turret for defense against infantry, and had a traverse of 15° left and 20° right, and could elevate 20° and depress 10°. Some thirty rounds of 150 mm ammunition were carried for the main armament, and 600 7.92 mm rounds for the machine gun. The StuiG required a crew of five to fully operated, comprising a driver, gunner, two loaders and a commander.
The StuiG had torsion bar suspension and a six speed forward, one speed reverse transmission gearbox. The maximum operational range of the StuiG was 110 kilometers, and the armor protection varied from 10 mm to 80 mm. The StuiG measured 5.4 meters long, 2.9 meters wide and 2.3 meters high, and weighed approximately 21,000 kilograms. The StuiG was built on the chassis of a StuG III Ausf. E assault gun, however other sources claim that the StuiGs were built on repaired chassis of StuG III Ausf. B, C, D and Es.
The StuiG was developed in 1941 by the Alkett company upon the Wehrmacht ordering new heavy assault guns. The StuiG was built on a dozen converted chassis of StuG III Ausf. Es, all of which were completed in December 1941 and January 1942, but none were issued to their units. On September 20, 1942 another dozen heavy assault guns were ordered, and all existing StuiG 33s were rebuilt. However, other sources claim that the StuiG was built on the repaired chassis of various StuG III assault guns, all twenty-four vehicles being produced by Alkett, starting in the September of 1942.
The first twelve StuiGs were delivered in the October of 1942 and issued to the Sturmgeschütz-Abteilungens 177 and 244, which were currently engaged in fighting at Stalingrad. The remaining twelve vehicles could not be delivered to the Sturmgeschütz-Abteilungens 243 and 245, which too were engaged at Stalingrad but had now been surround, along with the German Sixth Army, by Soviet forces. They were then subsequently formed into the Sturm-Infanteriegeschütz Batterie/Lehr Bataillon XVII, and attached to the 22nd Panzer Division during the ill-fated German attempt to relieve the encircled Sixth Army. Following the division's destruction during the fighting here, the battery was then permantly assigned to the 23rd Panzer Division, where it became the Sturm-Infanteriegeschütz Batterie/Panzer Regiment 201, also known as 9 Kompanie/Panzer Regiment 201, and remained with this unit for the rest of World War II. By the September of 1944, strength reports indicated that only five remained in service at the time. Only one remains today, and is located at the Kubinka NIIBT Research Collection near Moscow, Russia.