The idea of the tank with all of the characteristics later incorporated in the development of Panzerkampfwagen IV was originally laid down in the early 1930 by Heinz Guderian.
Panzer IV Ausf D was truly the first production model and remained in service until 1944.In October of 1938, further development of Pz Kpfw IV evolved into Ausf C and until August of 1939, 134 produced by Krupp-Gruson. Late Ausf C models were powered by newer Maybach HL 120 TRM, 12 cylinder engine with total power of 300hp.This engine became a standard powerplant for all of the later models of Panzerkampfwagen IV series. Overall early models (Ausf A/B/C) were development models and were mostly used for testing / training purposes while some were used in combat.The assemblies were attached to longitudinal twin quarter-elliptic leaf springs bolted to the hull.Above the road-wheels were 4 (reduced to 3 in Ausf J) return rollers on each side of the hull.Pz Kpfw IV Ausf D from 5th company of 2nd Panzer Division in Semois on May 12th of 1940.
Panzerkampfwagen IV was the main German tank of World War II, in action from September 1st of 1939 to May 9th of 1945.
First Panzerkampfwagen IV Ausf A was built in October of 1937 by Krupp-Gruson and its production ended in March of 1938 with total of 35 produced.
Ausf As were production / development prototypes and 5 were used for further testing while 30 saw combat service until 1941.
Rheinmetall-Borsig BW – VK2001(Rh) used Neubaufahrzeug‘s modified running gear, while Krupp’s BW – VK2001(K) and Maschinenfabrik Augsburg-Nurnberg AG’s VK2002(MAN) both used MAN’s newly designed running gear.
MAN designed new interleaved suspension system but it was not accepted.
It featured new front hull plate design (as Ausf A) and new external gun mantlet.