i think the fuel 'light up' does not mean it's empty. it just saying that the fuel is almost empty and need to be filled up. that's why we can drive a lil bit more km. but how many km i am not sure, and dare not to test. read somewhere it is not good for the engine, as it may collect dirt etc. at the bottom of the tank. (tapi ada dirt ke kat bawah tank tu? haha). even if what i read is not true, i still dun wan to try the limit of the fuel tank. kang minyak habis in the middle of nowhere tak ke haru?

if you can fill 42 liter, that's mean ur fuel tank is dry already.