How to Identify Engine Oil Viscosity?
4 Answers
Engine oil viscosity is categorized into winter and summer grades. The "W" stands for winter, and the smaller the number before it, the lower the viscosity, the better the low-temperature fluidity, and the lower the applicable minimum temperature. Summer oil grades are: 20, 30, 40, 50. The larger the number, the higher the viscosity and the higher the applicable maximum temperature. More details are as follows: 1. Engine oil, also known as engine lubricant, serves to lubricate and reduce friction, assist in cooling, seal against leaks, prevent rust and corrosion, and provide shock absorption. It is often referred to as the "blood" of a car. 2. SAE winter oil viscosity grades are: 0W, 5W, 10W, 15W, 20W, 25W. The "W" stands for winter, and the smaller the number before it, the lower the low-temperature viscosity, the better the low-temperature fluidity, and the lower the applicable minimum temperature. 3. SAE summer oil viscosity grades are: 20, 30, 40, 50. The larger the number, the higher the viscosity and the higher the applicable maximum temperature. 4. SAE all-season oil viscosity grades are: 5W-20, 5W-30, 5W-40, 5W-50, 10W-20, 10W-30, 10W-40, 10W-50, 15W-20, 15W-30, 15W-40, 15W-50, 20W-20, 20W-30, 20W-40, 20W-50. The smaller the winter number (indicating a lower applicable minimum temperature) and the larger the summer number (indicating a higher applicable maximum temperature), the broader the applicable temperature range.
Identifying oil viscosity is actually quite simple. With over 20 years of driving experience, I mainly look at the numbers on the oil container label. For example, the common 5W-30: the '5' before the W indicates fluidity during cold starts - the smaller the number, the smoother the startup; the '30' after W represents thickness at high temperatures - the higher the number, the better the engine protection. If I choose the wrong viscosity, like using oil that's too thin for long drives in hot weather, the engine will wear faster and fuel consumption increases - I once got startled when my car suddenly became noisier. Always check your owner's manual for recommended values - don't buy blindly based on gut feeling. Different vehicles have different requirements: SUVs often need 10W-40 while sedans commonly use 5W-30. During routine maintenance, check oil levels frequently and monitor color changes. Avoiding mixing different oil brands can extend engine life - I believe paying attention to these small details can save big money in the long run.
Oil viscosity identification starts from that label. The format like 5W-30 is standard design. I learned from DIY oil changes: 5 represents good winter fluidity, while 30 indicates stable high-temperature viscosity. A simple viscometer can measure actual viscosity, but for most people, reading the bottle instructions is the most reliable. Choosing the wrong viscosity carries significant risks, such as engine overheating or cold start failure. I often experiment in the garage and find that incorrect viscosity leads to increased fuel consumption and smoke. It's recommended to adjust according to seasons—use lower W numbers in winter and slightly higher in summer—but avoid frequent type changes. Additionally, check certifications like SAE standards on oil containers to ensure quality. I keep records of each oil change date to avoid forgetting and protect parts. Overall, trying it yourself is simple and fun.
Beginners can identify oil viscosity mainly by looking at the numerical combinations on the packaging label. For example, 5W-30 means faster flow in winter and thicker protection in hot weather. Always choose based on your vehicle's manual recommendations instead of guessing randomly. Using the wrong oil may cause increased engine noise or starting difficulties. Be careful not to buy the wrong type, and regularly check fluid levels to save on repair costs—it's simple and safe.
