Which is the summer oil 15W-40 .20W-50?20W-50 has a higher viscosity than 40, right?

W stands for WINTER winter, the number in front of W stands for pour point temperature, which is simply the freezing point temperature. 15W motor oil corresponds to the freezing point temperature of -20℃, 20W motor oil corresponds to the freezing point temperature of -15℃, the two oils have no problem to be used in the summer. the number after W stands for the oil's kinematic viscosity when it is in the 100℃, and the higher the value means the higher the viscosity.

Motor oil graded after the marking indicates its viscosity specifications, "W" the smaller the number in front of it indicates that the oil's low-temperature fluidity is better, representing the lower ambient temperatures available for use, the better the protection of the engine during cold starts, such as 5W represents the resistance to external low temperatures of -30 ° C, while the 20W resistance to low temperatures -15 ° C. The number after W represents the low temperature of -15 ° C. The number after W indicates the oil's kinematic viscosity at 100 ° C, which is no problem for summer use of the two oils. The number after W represents the kinematic viscosity of the oil at 100°C, the higher the value, the higher the viscosity. 40 represents the standard kinematic viscosity of 12.5mm2/s to 16.3mm2/s at 100°C, which is definitely not the case as claimed by some people that the oil can be used under 40°C.

This is the first time that the oil has been used for a long time, and it is the first time that the oil has been used for a long time.