1. The two oils are used in different occasions. Industrial gear oils are used for the lubrication of fixed industrial equipment gearboxes, while vehicle gear oils are used for the lubrication of mobile on-board gearboxes. The environment temperature of vehicle gear oil varies greatly, and it is mobile equipment, and the requirements for high and low temperature are relatively high. Therefore, vehicle gear oil needs to be divided into multi-grade and single-grade.

　　2. Vehicle gears for medium and heavy loads are generally hyperbolic gears, which have higher load-bearing requirements than industrial gears that are often cylindrical or conical. Therefore, the carrying capacity of medium-duty vehicle gear oil is equivalent to that of heavy-duty industrial gear oil. Therefore, medium-duty vehicle gear oil with a fairly viscosity grade can replace heavy-duty industrial gear oil, such as 90 GL-4 or 85W/90 GL-4, which can replace 220 CKD.

　　3. The viscosity grade of vehicle gear oil is classified according to the SAE regulations of the American Society of Automotive Engineers, and the kinematic viscosity at 100°C is measured. The industrial gear oil is classified in accordance with the requirements of the International Organization for Standardization ISO, and the kinematic viscosity at 40°C is measured. Therefore, the substitution must be converted.

　　4. In terms of classification, ISO only specifies the classification symbol C for industrial gear oils, and does not specifically specify the grouping symbol for vehicle gear oils. my country adopts API classification using GL-3, GL-4 and GL-5. This relationship is described in Appendix B of the Industrial Gear Oil Standard.

　　 In addition, the special evaluation methods of industrial gear oil in terms of friction and wear are mainly embodied in: four-ball test, Timken test and gear machine test. The vehicle gear oil must pass CRC L-37 (high-speed low torque, low-speed high torque) and CRC L42 (high-speed impact load) to assess its carrying capacity.

　　 Then, can automotive gear oil replace industrial gear oil?

　　 It is certainly not a simple replacement. If automotive gear oil can replace industrial gear oil, it must be professionally converted. However, it is certain that industrial gear oil cannot replace automotive gear oil. Moreover, when blending automotive or industrial gear oils, the dosage ratio of additives is different. Because the requirements of vehicles are much higher than those of industry, their working conditions are also different. Take SK6106 odorless gear oil compound as an example.

　　 The corresponding grade and addition amount of gear oil for vehicles are as follows: GL-3: 1.1%; GL-4: 2.1%; GL-5: 4.2%.

　　 The corresponding grade and dosage of industrial gear oil are as follows: CKC: 1~1.2%; CKD: 1.5~1.8%; CKE: 2~2.2%.