What does SL-5W40 engine oil mean?

[Julia]

SL-5W40 engine oil means: SL represents engine oil for gasoline engines, and 5W40 indicates the low-temperature flow performance and high-temperature viscosity of the oil. 5W40 oil can flow normally at temperatures as low as -20 degrees Celsius, and the high-temperature viscosity of this oil is 40. Here’s an introduction to engine oil: 1. Engine oil is the lubricant used in engines, composed of base oil and additives. 2. As a type of machinery, engines have common requirements for lubricants similar to general machinery, such as appropriate viscosity, certain anti-oxidation, anti-wear, anti-corrosion, and viscosity-temperature properties. 3. The density of engine oil is approximately 0.91×10³ (kg/m³), and it serves functions such as lubrication and wear reduction, auxiliary cooling, sealing and leak prevention, rust and corrosion protection, and shock absorption.

[VanJuliana]

SL-5W40 engine oil is a commonly used automotive lubricant. The 'SL' portion represents the API service classification, indicating this oil has excellent anti-wear and cleaning properties to combat engine deposits. The '5W40' is the viscosity rating: 5W means it flows quickly at low temperatures, making cold winter starts below zero easier, while 40 refers to maintaining stable viscosity at high temperatures to protect against engine overheating. I've used this oil many times and find it particularly suitable for regions with significant seasonal temperature variations, like northern areas with cold winters and hot summers. When selecting oil, always check your vehicle's manual recommendations and avoid arbitrary changes to prevent engine damage. Overall, it's a well-balanced motor oil, but don't exceed its service interval as that may affect performance.

[Phyllis]

As an oil enthusiast, I enjoy studying specifications like SL-5W40. The SL comes from the API (American Petroleum Institute) standard, indicating it has passed rigorous tests for aspects like oxidation stability and deposit control reliability. 5W40 is the SAE viscosity grade, with numbers divided into two parts: 5W shows it flows well at around -25°C, making it suitable for cold starts; 40 represents moderate viscosity at 100°C high temperatures, neither too thin nor too thick. In practice, it suits most modern gasoline vehicles with good compatibility, but I recommend regularly checking oil levels and change intervals. This oil is affordable yet practical - choosing the right one can extend engine life.

[Natalie]

SL-5W40 is the model label of engine oil. SL refers to the quality grade, meeting API standards, which proves its effectiveness in protecting the engine and reducing friction. The 5W40 part describes the viscosity performance: the 5W in front indicates smooth flow at low temperatures, making it good for winter starts; the 40 at the back indicates sufficient thickness at high temperatures to prevent engine wear from overheating. For us beginners, don't rush when choosing oil—first check the car manual to confirm the recommended viscosity grade, as this model might be suitable for environments with significant temperature changes. Simply put, it's like an all-purpose protective oil for cars, but it's best to go to a professional shop for maintenance to avoid issues.