Requirements of Diesel Engine Oil as it Relates to Low Temperature Operation

The performance requirements of heavy duty engine oils designed for equipment operating at ambient temperatures of less than −25°C are discussed. Experience has shown that the use of properly formulated, partially synthetic SAE 5W20 “Arctic” oils can lead to improved startability and actually increase equipment life and engine durability- A further benefit may be realized through an increase in fuel economy over that of heavier oils. Even better performance may be obtained through the use of partially synthetic SAE 5W30 “Arctic” oils which are useful over a wider temperature range and allow operation of equipment at ambient temperatures consistently below −40°C. Finally, recommendations by various engine manufacturers and the US military regarding low temperature operation of diesel engines is reviewed.