What's the difference between 5w and 0w?
4 Answers
The differences between 0W and 5W engine oil are as follows: 1. Different low-temperature viscosity: Low-temperature viscosity refers to low-temperature fluidity. W is the abbreviation for winter in English. The number before W represents the low-temperature fluidity of the oil. The smaller the number, the lower the low-temperature viscosity of the oil, the better the fluidity, and the more resistant it is to low temperatures. 2. Different low-temperature resistance: Generally, 0W oil can be used at temperatures as low as -35°C, while 5W oil can only withstand temperatures as low as -30°C. As the temperature decreases, the oil becomes thicker, increasing the resistance when starting the engine. If oil with poor low-temperature fluidity is used in extremely cold conditions, it may cause the car engine to start weakly or even fail to start.
The difference between 5W and 0W engine oil types essentially boils down to their performance in cold weather. 5W can handle temperatures down to around -30°C, making the engine turn over more smoothly during startup. It's suitable for most regions—for example, I drive year-round in the Yangtze River Delta, and 5W-30 oil works perfectly fine. I've never encountered cold-start issues in winter, and it's more budget-friendly. 0W is thinner and performs reliably below -35°C, making it ideal for extremely cold areas like Northeast China or Inner Mongolia during winter. It ensures quicker cold starts and reduces engine wear, but its drawback is that in high summer temperatures, its lubrication stability may not match 5W. I've tried it a couple of times in Hainan, and the experience was mediocre. In short, the choice depends on your location and driving habits: 0W excels in colder regions, while 5W is worry-free in warmer areas—don’t just chase affordability over practicality. When checking oil, always consider the overall viscosity, not just one number.
As an average car owner, I think the main differences between 5W and 0W lie in cold-start performance and fuel consumption. 5W works fine at -30°C—the car starts normally, which is perfect for Beijing winters. But in even colder regions, you might notice slower engine starts and some noise. 0W, with better fluidity, ensures smooth starts in extreme cold like -40°C in Xinjiang, protecting the engine and reducing cold wear for longer lifespan. In terms of fuel economy, 0W usually saves about half a liter due to lower lubrication resistance, making it cost-effective for daily use, especially with synthetic oil in the long run—though it's slightly pricier. For southern cities, 5W is sufficient—no need to overspend. Always check your manual and avoid switching arbitrarily to prevent insufficient lubrication and part damage. Choose the right oil based on your local temperatures.
From the perspective of daily driving, the difference between 5W and 0W oil lies in cold-weather performance. 5W oil has a minimum operating temperature of around -30°C with decent fluidity, making it suitable for ordinary regions. I've used it in Jiangnan for years with smooth startups and adequate engine protection. 0W oil performs better in extremely cold conditions below -35°C, making it ideal for frigid zones like Northeast China—it ensures quicker startups, reduces initial friction, and minimizes engine wear. However, note that 0W oil has weaker viscosity at high temperatures, which may affect lubrication during long-distance driving. It's advisable to pair it with a higher second viscosity grade (e.g., 0W-20) and regularly check oil condition. Never overlook regional differences—choosing the right oil is crucial.
