The index of level of fuel in a tank shows approximate amount of the fuel which is available in a tank (fig. 1.55)
. In due time fill the fuel tank. You watch that the amount of fuel in a tank never decreased lower than a quarter of full capacity of a tank. If the signaling device of the minimum level of fuel in a tank lit up or the arrow of the index is about a mark "E" (Is empty), immediately fill the fuel tank.