The self-propelled tank destroyer M18 "Hellcat" represented the most advanced development of the American technique in this specific branch of armored vehicles during the Second World War. It was born from the later development of an idea that had already led to the construction of the preceding M10, which had demonstrated to be a valid enough formula. In practice it was a model created "ex novo" with a specially conceived hull, initially armed with the same 76.2-millimeter cannon of the M10, and later with more powerful pieces, such as the 90-millimeter cannon and the 105/22 howitzer. But these last models remained in the stage of prototype, whereas the M18 not only had a great success, but also after the war it was acquired by numerous armies that used it during many years. In the early 1970s some M18 still operated in the armored forces of the Yugoslavian Army.

But let us return to the beginning of the operative life of this vehicle. Above all it should be mentioned that the M18 was the fastest armored vehicle on the entire war. Its engine, a radial Continental of nine cylinders and 400 horsepower, was able to make it reach the surprising speed on road of 72 kilometers/hour. Naturally, to obtain this amazing result the entire constructive concept had to be changed. Just to make a comparison, the vehicle would not be like a heavy battleship, well protected but limited by the weight of thick steel plates, but rather like a cruiser, lightly armored but fast and very maneuverable, and above all fitted with weapons that, exploited along with its mobility, could put in trouble any German armored element in use in that time.

The hull of the vehicle, formed by plates welded to each other in such a way that they formed multiple sloped surfaces to divert the projectiles, in its maximum thickness point had only 13 millimeters. On the contrary, the 76-millimeter cannon installed in rotary turret was able to perforate 175 millimeters of armor from little less than one kilometer of distance. When they were demonstrated the services that this vehicle could offer in the battlefield (already in the beginning of 1944), it was decided to force its production to be able to experiment "live" the weapon. So, after only nine months the American war industry managed to build some more than 2500 of these tank destroyers, about 277 per month, which were all used by the United States Army.

From the operative standpoint, the Hellcat kept up to the expectations that had been put on them, managing to destroy a discreet number of German tanks with relatively low losses. Besides it should be considered as well that if vehicles are easily "rolled", more time is needed for the personnel, and that the American tankers were not used, unlike the German adversaries, to a fast war of ambushes fought with armored vehicles.