
SL is the lowest grade of engine oil. Below is an introduction to engine oil grades: 1. API (American Petroleum Institute) classifies engine oil grades from SA to SN, etc. This label actually describes the quality of the oil. The further back the letter after 'S' is in the alphabet, the higher the quality of the oil. So far, SN is the highest grade. If the series starts with 'C', it represents diesel engine oil, with specifications including: CA, CB, CC, CD, CE, CF, CF-2, CF-4, CG-4, CH-4, CI-4. When both 'S' and 'C' letters are present, it indicates that the oil is suitable for both gasoline and diesel engines. 2. SN grade is currently the highest grade of engine oil. SJ was the standard in the 1990s, SL was the standard in 2001, SM was the standard in 2004, and SN became the standard in 2010. The best SL-grade oils are mainly semi-synthetic or mineral oils, while SN-grade oils are all fully synthetic, representing the highest standard of engine oil.

SL-grade motor oil is one of the service classifications by the American Petroleum Institute (API), specifically designed for gasoline engines. Having driven many cars, I can say the SL standard emerged around 2001, offering decent oxidation resistance and cleaning performance, which helps reduce engine wear and carbon buildup. It's well-suited for older vehicle models, particularly those from the early 2000s. However, newer standards like SP or SN are more advanced today, with superior oxidation resistance. If you own an older car, I recommend regularly checking your oil grade—using SL can save you money, but always ensure it matches your vehicle manual's recommendations. Don’t wait until engine issues arise to change it; this is crucial for extending your car’s lifespan, especially with frequent stop-and-go city driving.

As a student car owner commuting near campus, I pay attention to API standards when selecting engine oil. The SL grade was quite popular in the 2000s, offering good wear protection and being cost-effective for most older family cars. During routine maintenance, I've found that using SL oil helps keep the engine running quietly and reduces fuel consumption. However, modern oils like SN offer higher performance and better environmental compliance. When changing oil, don’t buy blindly—checking the vehicle’s manual is crucial, as using the wrong oil can shorten engine life. For young people, saving on car maintenance costs is important, but safety comes first. Don’t skip regular oil changes, and combine them with other maintenance tasks like checking filters to avoid roadside emergencies.

Having driven for so many years, I'm very familiar with SL-grade engine oil. It's an early API classification standard, primarily improving engine cleanliness and reducing internal carbon deposits. It's cost-effective for older cars, but newer models are recommended to use higher grades like SN or SP for better corrosion protection. Delayed oil changes may lead to engine knocking or sluggish acceleration, which is crucial based on experience. Regularly checking oil condition is fundamental to car maintenance, but don't neglect other aspects like the cooling system.

When selecting SL-grade motor oil, engine safety protection is a crucial consideration. This grade offers excellent oxidation resistance and wear protection, helping keep the engine cleaner and more durable, especially for older family vehicles. With proper oil change intervals, it can prevent common issues like power loss. Combined with cabin air quality optimization measures such as cleaning the AC filter, the overall driving experience becomes more comfortable and reassuring. For daily use, avoid expired oil products - regular maintenance forms the fundamental step that's vital for family safety.


