Since the introduction of liquid coolant as the heat transfer media for internal combustion engines, improvement of the coolant’s performance and properties has always been a key developmental priority. The drive for improved fuel economy and the development of lighter, more compact powertrain designs often result in the need for improvement in the performance and properties of the coolant. The adoption of new and more effective manufacturing technologies and design changes to key cooling system components also contributes to the need for these improvements. Recently, the focus has been on improvement to the longevity of the corrosion protection performance of the coolant. This will allow for extended service life which will lessen environmental impact, reduce operating/maintenance cost, and ensuring continuous improvements of system reliability and durability. In this paper, the major technological developments of extended life coolant products for automotive use, since the 1990 s, are reviewed. Laboratory and fleet test data on several different key extended life coolant products will be presented and compared to demonstrate their performance and areas for potential improvement. The development of the next generation of extended life coolant technologies with improved performance and a longer service life will be discussed.