Changing Coolant : Necessary or not ?

There are only very, very minute proportion of engines left over earth that still needs air cooling. Either they are so small or well engineered or very badly engineered. Oil cooling or liquid cooling has taken the charge and air cooled engines have just became a thing of past for many manufacturers. So, with more efficient, cool & reliable engine most people get out of tone of maintaining a coolant. Well, some might think it doesn’t need to be replaced, no it’s not! Engine coolant is...