Despite its success in combat the Tiger continued to experience many problems. The overlapping suspension was one, which could easily become clogged with mud. During the Russian winter, this mud would freeze and would need to be chipped away before the tank could move. The engine was due to be replaced by the Maybach HL234, which was being developed. Essentially, this was the current HL230 engine extensively upgraded and modified with the fitting of fuel injectors which would have risen the engine power to 800-900hp partially addressing the underpowered issue. Although, this engine though never reached production before the war ended. This was to address the same under-powered problem suffered by the Tiger.
In comparison, a modern British Challenger 2 tank which has a weight of 62 tons with much stronger Chobham 2 armour, a more powerful 120 mm gun and a V-12 diesel engine producing 1,200hp. This gives a power to weight of 19.2hp compared 13.8hp for the Tiger I and 10hp for the Tiger II. At the same time, it shows how advance the Tiger II was for its day. With tank engine and transmission technology at the time, being the only real weak area Germans had not overcome.
Only 492 King Tigers were produced, with production being severely disrupted by allied bombing raids. The King Tigers turret was designed to mount the 8.8 cm KwK 43 L/71 gun. The KwK 43 was over 1.3 meters longer than that of the 88 mm KwK 36 L/56 used for the Tiger I. The cartridge was also considerably longer and wider than that used in KwK36, allowing for a much heavier propellant charge. The guns’ extremely high muzzle velocity and operating pressures caused accelerated barrel wear, resulting in a change to a two-piece barrel. This made it much easier to change worn out barrels. The turret could be rotated 360 degrees in 60 seconds in low gear, in 19 seconds in high gear at idle engine speed, and within 10 seconds at the maximum allowable engine speed in high gear. Making it quickly able to swing round onto a target.
After initial success in Normandy in July 1944, the Tiger II or King Tiger made it to the Eastern Front. It was first used in anger on August 12, 1944 by the 501st Heavy Panzer Battalion resisting the Lvov–Sandomierz Offensive. The King Tigers attacked a Soviet bridgehead over the Vistula River near Baranów Sandomierski. However, on the road to Oględów, three Tiger IIs were destroyed in an ambush by a few T-34-85s. Due to these German tanks suffered ammunition explosions, which caused many crew fatalities. This also led to main gun ammunition no longer being stored in the turret to reduce fatal explosions. In doing so this reduced the number of rounds carried to 68. On August 11, 1944, three King Tigers approached and started to attack a bridge over the Vislula River. However, as they began their attack they had already been spotted by Oskin a Red Army tank commander. His T-34-85 along with two others had been well hidden and heavily camouflaged. They also had an SMG platoon supporting them.
Rather than engage straight away he decided to wait until the three King Tigers were much closer and more likely to suffer fatal damage. He waited until the King Tigers were about 200 metres away and opened fire. The King Tigers were side on to the T-34-85s and at this range, the D5-T gun should be able to penetrate the side armour. Using both APDS (Amour Piercing Discarding Sabot). Which is kinetic energy projectile that enabled better penetration of thick armour. The first two rounds fired on one King Tiger did not penetrate the third hit the turret and caused the ammunition stored in the turret to exploded lifting it away from its turret ring. The explosion also caused the King Tiger to catch fire killing all its crew in an instance. The King Tigers had yet to find their target let alone fire off any rounds. The T-34s continued to fire and another King Tiger was hit three times but its armour was not penetrated as they turned into the line of fire with their much stronger frontal armour. A fourth round hit just underneath the main turret and again caused ammunition to explode killing the entire crew once again. Two mighty King Tigers were now burning ferociously without a single T-34-85 having been hit. Out in the open and nowhere to hide, the final Tiger decided to try and escape by moving at full-speed. Using smoke, the T-34s used their greater speed and manoeuvrability and managed to outmanoeuvre the King Tiger. The T-34s fired off several shots into the side of the King Tiger.