Volume 3, Issue 10 (November 2006)
Coolants at Elevated Temperatures
Over the years, new performance requirements and environmental regulations have driven engine manufacturers to design new engines. The new engine technologies have resulted in different operating conditions in cooling systems. In general, a trend towards higher coolant temperatures is observed, which is expected to have an implication on the coolant stability and corresponding lifetime. In heavy duty applications, this trend is even more pronounced as engines are running longer and under more severe conditions. In this paper, a selection of different current coolant technologies available in the market have been tested to obtain more information on the influence of the coolant additive package on the thermal stability of the most commonly used coolant base fluid, mono ethylene glycol (MEG). For this reason glycol oxidation products have been measured after subjecting the coolants to high temperature oxidative conditions. In addition the physical/chemical stability of the coolants and corrosion protection level of the additive packages have been evaluated.