The heaviest tank ever constructed was the German Panzerkampfwagen Maus II, which at 192 tonnes (423,287 lb) weighed as much as 130 modern saloon cars. By 1945 it had reached only the experimental stage and was abandoned.
The heaviest operational tank used by any army was the 75.2-tonne (165,787 lb) 13-man French Char de Rupture 2C bis of 1922. It carried a 15.5-cm. (6.1-in.) howitzer and was powered by two 250-hp. (186 kW) engines giving a maximum speed of 12 km./h. (7.5 mph).
Comments below may relate to previous holders of this record.