it is my understanding that the radiator has 50% water and 50% radiator fluid. how do I know which of the 2 has run out? i have never opened the radiator cap before. is there a level checker thing inside it to check the fluid level? if the fluid is low do i put some more water or radiator fluid in it?
i haven't got any radiator fluid but can i buy it from a car part shop?
i don't know what brand of radiator fluid my car currently has so if i buy some from the shop would it matter if it was a different brand?
with regards to the oil. i don't know what brand of oil my car currently has. i see some brands have different advantages etc. if i bought some oil from the shop would it matter if it was a different brand of oil that is in my car right now?
will anything bad happen if the car has a mixture of 2 different brands of oil?
and by the way, what colour is the oil when its dirty?