The weapon has been used against tanks effectively because of the conformation of parts of tanks, particularly around the undersides and fuel tank "entrances". A Molotov cocktail could blow up the fuel tank, destroying the machine, particularly for older (before 1940) tank models. Molotov cocktails are much more effective against gasoline engines than diesel engines' tanks. This is because diesel has a high flashpoint of 64 °C – making it more difficult to ignite compared to petrol. Some Soviet tanks actually had an entry to the gas tank on the side of the vehicle, which could be opened by combatants in close quarters, letting out the highly flammable liquid and making destruction of the tank even easier. Note that these tactics were only effective due to the advantage guerrillas had in close quarters; tanks can barely maneuver in such conditions and are not able to counter quick-moving enemies armed with incendiary bombs.