What is the difference between 5w and 10w engine oil grades?

[VanBella]

The differences between 5w and 10w engine oil grades: 1. Freezing point temperature varies: The freezing point of 5w oil is -30°C; The freezing point of 10w oil is -25°C. 2. Low-temperature fluidity differs: 5w oil has better low-temperature fluidity; 10w oil has poorer low-temperature fluidity. 3. Applicable temperature ranges differ: 5w oil has a narrower applicable temperature range with lower maximum temperature; 10w oil has a broader applicable temperature range with higher maximum temperature than 5w. 4. Wear reduction effects vary: 5w oil has poorer wear reduction performance; 10w oil has better wear reduction performance.

[DeAngelina]

When I first started learning about car maintenance, I was also curious about this. The main difference between 5W and 10W oil lies in their performance in cold weather. The 'W' stands for winter temperature fluidity—the smaller the number, the better it performs in cold conditions. 5W flows more smoothly at temperatures below -30°C, making engine starts easier and reducing wear; 10W is sufficient for slightly warmer areas, around -20°C, but starts may be slower in extreme cold. In high temperatures like summer, the difference between the two is minimal, though 10W maintains viscosity better under heat. Your choice depends on your living environment—I switch to 5W in northern winters for better protection, while friends in the south can manage with 10W and sometimes save money. Never choose randomly, as insufficient lubrication can shorten engine life. A quick glance at your owner’s manual recommendations will make it clear.

[DeMax]

As a veteran driver with over a decade of experience, I recommend choosing engine oil based on local climate conditions. 5W flows better in low temperatures, ensuring smooth cold starts in sub-zero winter weather and reducing engine wear. 10W has slightly poorer flow characteristics, resulting in slower cold starts, but performs similarly in summer with more stable oil film at high temperatures. Having used both types, I stick to 5W in cold regions for responsive performance, while switching to 10W during vacations in hot areas without issues. The key is not to compromise on quality - cheap oils damage engines regardless of viscosity rating. Make it a habit to check oil levels every 5,000 kilometers for proper vehicle maintenance and safety.

[McEleanor]

Simply put, the numbers in 5W and 10W engine oils indicate cold-weather fluidity. The smaller 5W number means faster flow, suitable for extreme cold; 10W flows slightly slower, better for mild winters. When temperatures rise, their performance becomes similar. Choosing wrong may cause difficult engine starts or slightly higher fuel consumption. It's best to check your owner's manual or local temperatures to decide.