Comparison of Extended Life Coolants in Laboratory Testing

The strengths and weaknesses of engine coolants based on organic acid inhibitors are investigated. Recently, this technology has been approved for use by major OEM's. The coolants are expected to have a service life of at least 5 years/160,000 km as compared to the recommended 2 years/48,000 km for conventional silicate inhibited coolants.

Laboratory performance tests of commercially available ethylene glycol based coolants and experimental propylene glycol based coolants are presented. These include physical properties measurement, ASTM corrosion tests, compatibility of OA and silicate coolants, tests to stress coolant performance, and electrochemical tests.