What is the difference between 10w40 and 5w30?
2 Answers
The differences between 10w40 and 5w30 include applicable temperature ranges and oil viscosity. The specific details are as follows: Different applicable temperatures: The freezing point temperature for 5W oil is -30 degrees Celsius, while for 10W oil it is -20 degrees Celsius. 5W30 oil has better cold resistance than 10W40, meaning it can be used at lower temperatures and offers better cold start performance. Different oil viscosities: The numbers 30 and 40 indicate the high-temperature viscosity of the oil. 10W40 oil has higher viscosity than 5W30, providing better high-temperature protection and sealing performance. However, higher viscosity does not always mean better performance. Excessive viscosity can increase engine operating resistance, leading to insufficient engine power and increased fuel consumption.
I've driven many cars and have some insights about engine oil. The main difference between 10W40 and 5W30 lies in their temperature adaptability. Simply put, 5W30 starts more smoothly in severe winter conditions, such as temperatures below -20°C, as it flows faster and the engine starts immediately when you turn the key. 10W40 starts a bit slower in cold weather but offers better protection in high summer temperatures, keeping the engine quieter during long-distance drives. Why? The 'W' stands for winter performance—the smaller the number, the better the low-temperature performance. The latter numbers '30' and '40' indicate high-temperature viscosity—higher numbers mean thicker oil, which provides better protection but slightly higher fuel consumption. I once used the wrong type—5W30 in summer made the engine feel weak, while 10W40 in winter caused hard starts with the engine struggling. Now, I follow the manufacturer's recommendations, regularly check the manual, and avoid blindly following trends. Choosing the right oil saves fuel, extends engine life, and makes maintenance easier.
