The low-temperature viscosity of anhydrous coolant is reduced by adding ethylene glycol to the propylene glycol base fluid, and the evaluation method of low-temperature fluidity is also studied. The experimental results show that the low-temperature fluidity of anhydrous coolant can be greatly improved by the participating of ethylene glycol. Freezing point method is usually used for measuring the low temperature performance of coolant, but for “long icing process” anhydrous coolant, beginning-crystal point shows more practical reference value. Therefore, freezing point, beginning-crystal point and low-temperature fluidity should be considered at the same time when evaluation the low temperature performance of anhydrous coolant.

Ultrasonic vibratory cavitation erosion tests were carried out on studying the cavitation erosion protection performance of different type of heavy-duty engine coolants for cast iron material of wet sleeve cylinder liners. The influence of coolant type, freezing point, corrosion inhibitor content and test duration on anti-cavitation performance were analysed. The experimental results showed that the anti-cavitation erosion performance of organic acid type heavy-duty engine coolants were better than the inorganic salt type heavy-duty engine coolants. For the same formulation coolant, increasing the content of ethylene glycol or corrosion inhibitor can improve the anti-cavitation erosion performance. With the extension of ultrasonic vibration test time, the anti-cavitation erosion protection performance for cast iron was reduced.