In the Gathering Storm expansion, the Mechanized Infantry requires 1 Oil to train and 1 Oil per turn to maintain.
This is the strongest melee unit in the game, a serious upgrade from the more simple Infantry. Soldiers are now equipped with the latest small arms - and even more importantly, APCs to move them around. This makes them faster, and for the first time in the game a front-line unit has more than 2 Movement. Of course, this rarely helps them keep up with Tanks and other advanced cavalry units, but at least they now have a fighting chance. Besides, the Mechanized Infantry is the "cheapest" of the late game units, because it requires no difficult-to-find resources (until Gathering Storm).
Despite technically being an armored vehicle, it is not vulnerable to the Modern AT, quite the contrary!
Civilopedia entry Edit
With the coming of the gasoline engine to the battlefield, and all those tanks and trucks zipping about, the foot-slogging infantry had trouble keeping pace. Between the world wars, various nations studied how this could be improved. But it was Nazi Germany, with its emphasis on blitzkrieg, that devoted the most attention to “mechanizing” the infantry to keep up with their panzers before they tore across Poland, France, North Africa and Russia. Since trucks couldn’t quickly traverse the sort of ground encountered in these places, the German engineers had designed the first half-track (the Sd.Kfz 251) to carry infantry and their supplies while keeping up with the tanks. Add in some tracked artillery and AA guns, and one had an independent battlegroup, capable of holding its own against anything the enemy had. So successful were the Germans that every other combatant emulated them, to the point where most infantry today are “mechanized.”
The Mechanized Infantry's model is based on the M1126 Stryker ICV.