Which has higher viscosity between 0w30 and 5w30 engine oil?
2 Answers
0w30 and 5w30 engine oils have the same viscosity, but differ in low-temperature flow performance. Engine oil, also known as motor lubricant, serves multiple functions for the engine: lubrication and friction reduction, auxiliary cooling, sealing and leak prevention, rust and corrosion protection, as well as shock absorption. The meanings represented in engine oil grades are as follows: 1. The number before 'w' indicates the oil's low-temperature flow performance; 2. 5w means the oil can flow normally at -30 degrees Celsius; 3. 0w indicates the oil can flow normally at -35 degrees Celsius; 4. The number after 'w' represents the oil's high-temperature viscosity, with higher numbers indicating greater viscosity.
I often help friends with their car oil issues. Actually, the biggest difference between 0W30 and 5W30 lies in their low-temperature fluidity. The number before the W represents the low-temperature viscosity grade. 0W can maintain fluidity at -35°C, while 5W is suitable for a minimum of -30°C. When temperatures drop below -25°C, 5W30 becomes much thicker than 0W30, requiring more effort from the oil pump during cold starts. As for high-temperature viscosity—the number 30 after the W—they are exactly the same, with no difference in viscosity under normal engine operating temperatures. So strictly speaking, 5W30 has higher viscosity at low temperatures, a difference that northern car owners know best: last winter, my car with 5W30 had noticeably more difficulty starting in the morning compared to my neighbor’s car using 0W30. After switching oils, the issue was resolved. The key to choosing oil depends on local temperatures. In places like Heilongjiang, 0W30 is definitely the first choice.
