What is the difference between 0w30 and 5w40?
3 Answers
0w30 and 5w40 differ in the following ways: 1. Both specifications have the same viscosity grade at 100°C. 2. The main difference lies in the low-temperature flowability indicated by the number before the W. 3. The smaller the number before the W, the better the low-temperature performance, which represents the low-temperature viscosity grade. 4. The larger the number after the W, the higher the viscosity of the oil, indicating the high-temperature viscosity grade. Here is some additional information about oil viscosity: 1. Oil viscosity index can be divided into three levels. 2. 35 to 80 is considered medium viscosity index oil. 3. 80 to 110 is high viscosity index oil. 4. Above 110 is ultra-high viscosity index oil.
I often drive long distances from my hometown, especially in winter when temperatures can drop below minus ten degrees Celsius, and I've used different oils. The 0W30 has a lower viscosity in cold temperatures, flows faster during cold starts, makes the engine easier to fire up, and reduces wear; in comparison, 5W40 is a bit thicker at the same low temperatures, so starting might be slower. In summer or during high-speed driving, the 0W30's high-temperature viscosity of 30 is relatively thinner, offering better fuel economy, but it provides weaker protection under aggressive driving. The 5W40's 40 viscosity is thicker, forming a more robust oil film at high temperatures, protecting engine components under heavy loads, making it suitable for those who frequently drive long distances or carry heavy loads. When choosing oil, always refer to the owner's manual recommendations and avoid random switches, as it may affect performance and longevity. I recommend prioritizing 0W30 in cold regions and considering 5W40 in hot climates or for older cars to balance protection and fuel consumption.
I commute in a family car, driving dozens of kilometers every day, and I care about fuel costs and engine health. The advantage of 0w30 lies in its strong low-temperature fluidity, ensuring smooth cold starts in the morning and reducing engine wear; 5w40 is slightly inferior in this aspect. At high temperatures, the 30 viscosity of 0w30 makes the engine run more fuel-efficiently, especially during low-speed driving. Conversely, the 40 viscosity of 5w40 is more robust at high temperatures, providing stronger protection for internal components, making it suitable for roads in frequently hot regions. The overall difference is minor, but long-term use of the wrong oil can increase maintenance costs. Personally, I feel that 0w30 is more economical for new cars or gentle driving, while 5w40 is better for older cars or frequent heavy loads. During maintenance, regularly check the oil condition—don’t skimp on this expense.
