system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How are Molotow cocktails effective against armored vehicles?

I feel like these very robust vehicles should withstand some fire on the surface of their armor. Isn‘t this what they are designed for?
gpt
Fire on armor isn't the problem. All of those vehicles are going to have various orifices for things: Hatches, optics, and most importantly ventilation. The crew inside will need constant air supply along with the engines.

It turns out that the air intake to an APC doesn't do very well when it is covered in flaming gasoline. They suck in smoke and air with most of the oxygen combusted out of it. Engines can be stalled, and crew tends to react poorly to being inside a metal box full of smoke and low oxygen air.

Various gaskets can also be damaged by the high temperatures, and the view outside temporarily obstructed. Hitting an armored vehicle with several Molotov cocktails isn't going to *destroy* the vehicle in itself, but it might force the vehicle to stop and the crew to get out. Outside the vehicle the crew are much more vulnerable, both to small arms fire and more Molotov cocktails.