Tiger I nickname "Tiger" by Ferdinand Porsche, and the Roman numeral was added after the later Tiger II entered production. The initial designation was "Panzerkampfwagen VI Ausführung H" (‘‘"Panzer VI version H"’’, abbreviated "PzKpfw VI Ausf. H") where 'H' denoted Henschel as the designer/manufacturer. It was classified with ordnance inventory designation "SdKfz 182". The tank was later re-designated as "PzKpfw VI Ausf. E" in March 1943, with ordnance inventory designation "SdKfz 181". Today, only seven Tiger I tanks survive in museums and private collections worldwide. The Tiger 131 at the UK's Tank Museum, which was captured during the North Africa Campaign, is
Tiger II from research, training, and a five-tank attachment to the Panzer Lehr, the Tiger II was only issued to heavy tank battalions ("schwere Panzer-Abteilungen") of the German Army ("Heer"), or "Waffen-SS". A standard battalion ("Abteilung") comprised 45 tanks: Units that used the Tiger II were as follows: Early Tiger IIs proved unreliable, owing principally to leaking seals and gaskets, and an overburdened drive train originally intended for a lighter vehicle. The double radius steering gear was initially particularly prone to failure. Lack of crew training could amplify this problem; drivers originally given only limited training on other tanks were often sent