The Difference Between 10w30 and 5w30
3 Answers
Here are the differences between 10w30 and 5w30: 1. High-temperature viscosity: The larger the number, the better the high-temperature performance. 2. Low-temperature viscosity: The smaller the number before W, the better the low-temperature performance. 3. 5W-30 has better fluidity than 5w-40, which can reduce fuel consumption and allow the engine to dissipate heat faster. 4. 5W-40 is more stable than 5W-30 under high-temperature conditions of the engine. Additional information about engine oil: 1. 10W-30 is suitable for temperatures down to -18 degrees Celsius; if the temperature is lower than -18 degrees Celsius, 5W-30 should be used. 2. 5W-30 has high-temperature limits and is suitable for use below 40 degrees Celsius; the maximum applicable temperature for 5W-30 will drop to around 15 degrees Celsius.
The difference between 10W30 and 5W30 mainly lies in winter performance. I usually drive in the northern region, where 5W30 is more suitable for cold weather because the smaller the number before the W, the better the low-temperature fluidity. Since 5 is smaller than 10, the oil flows faster at temperatures below zero, allowing the engine to start quicker and reducing wear. 10W30 is slightly thicker at the same low temperatures, which may cause slower starts. At high temperatures, both are rated 30, meaning they have similar viscosity with no significant difference. When choosing oil, I consider the climate. Since winters in my hometown are cold, I use 5W30. In the warmer summer months, I might occasionally use 10W30 to save some money, but the manual is always the primary reference. Switching oils randomly could affect fuel consumption or engine lifespan.
I've been repairing cars for almost ten years, and you really can't just randomly choose the SAE grade of engine oil. Both 10W30 and 5W30 are multi-grade oils, but the difference lies in their cold-start viscosity. The number '5' before the W indicates better low-temperature fluidity, making it more suitable for smooth starts in environments as cold as -30°C. On the other hand, 10W30 can barely flow at -25°C, offering slightly weaker low-temperature protection. As for the high-temperature performance, both are rated at 30, so there's no difference in protection once the engine is warmed up. I recommend car owners choose based on their local climate: use 5W30 in cold regions to avoid dry friction during engine starts, while 10W30 is sufficient and more cost-effective in warmer southern areas. Always remember to stick to the viscosity recommended in your vehicle's manual—exceeding it can easily lead to problems.
