What Are the Standards and Classifications of Engine Oil?

[Charles]

The classification of engine oil typically follows two methods: viscosity grading and oil quality grading. Here are the detailed explanations: 1. SAE Viscosity Grading: According to the viscosity classification method, lubricating oils are divided into three types: high-temperature type for summer, low-temperature type for winter, and all-season type suitable for both winter and summer. (2) High-temperature type for summer: 20, 30, 40, 50. The larger the number, the higher the viscosity, and the higher the maximum applicable temperature. (2) Low-temperature type for winter: 0W, 5W, 10W, 15W, 20W, 25W. The symbol W stands for Winter, and the smaller the number before W, the lower the low-temperature viscosity, the better the low-temperature fluidity, and the lower the minimum applicable temperature. (3) All-season type: 5W-20, 5W-30, 5W-40, 5W-50, 10W-20, 10W-30, 10W-40, 10W-50, etc. The smaller the number before W, the lower the minimum applicable temperature of the oil, and the larger the number after W, the higher the maximum applicable temperature. Since this type of oil is suitable for various operating conditions, all-season oil is widely used and recommended by major automobile manufacturers. 2. Oil Quality Grading: API engine oils are divided into two categories: one is oil starting with S, which is suitable for gasoline engines, and the other is oil starting with C, which is suitable for both gasoline and diesel engines. (1) Oil starting with S: This type of oil starts with S, and the letters range from A to N. Each subsequent letter represents a higher grade than the previous one. For example, SN is a higher grade than SM. (2) Oil starting with C: This type of diesel engine oil follows a similar grading system as the S-grade oil. The further the letter is in the alphabet, the higher the oil grade.

[Reagan]

I've been pondering oil standards for quite some time. The SAE viscosity classification is fundamental. For example, in 5W-30, the 'W' stands for winter suitability, and the number 30 indicates the oil's thickness at high temperatures, making it suitable for various weather conditions. The API rating focuses more on protection performance, with SP being the current mainstream standard for gasoline vehicles, offering better engine cleanliness and wear resistance, while SN is the older version. ILSAC standards like GF-6A emphasize fuel economy and emission reduction. Additionally, Europe has the ACEA rating, such as A5/B5, which leans towards fuel-saving designs. Don’t overlook the certification labels—the small icons on the bottle can help you quickly identify compatibility. Remember to choose based on your driving environment: in northern winters, opt for oils with good cold-start performance, while in high-temperature areas, select oils with stable viscosity. Checking the owner’s manual can prevent wrong choices that might harm your car. Regularly changing this stuff is crucial for engine health.

[PiperDella]

As someone who drives to work every day, I understand oil standards quite simply: SAE viscosity grades like 0W-20 mean the oil is thinner in winter for easier starts, API ratings starting with S (like SP) are for gasoline engines, while C ratings are for diesel engines, protecting against engine wear. ILSAC certifications like GF-6B focus more on fuel efficiency and emission reduction. When choosing oil, check the bottle labels—don't randomly use high or low viscosity oils; I once used the wrong oil and experienced higher fuel consumption. High-mileage oils are better for older cars, with moderate viscosity to prevent leaks. The maintenance manual is the golden rule—it specifies the oil type for safety. Ambient temperature affects oil performance: use multi-grade oils in cold regions, and avoid cheap, low-quality products in tropical areas.

[Jean]

I just learned about car maintenance, and oil standards aren’t that mysterious: SAE classifies viscosity, with 0W-30 being a thinner oil for quicker starts; API ratings like SP are newer versions, improving anti-contamination performance; ILSAC ratings like GF-6A help save fuel. When choosing oil, checking the vehicle manual is crucial—it directly states the required SAE and API specifications. I once neglected this and used mismatched oil, causing abnormal engine noise. A friend reminded me that high-mileage-specific oil extends the lifespan of older cars, with moderate viscosity preventing leaks. In regions with significant temperature changes, matching the oil grade avoids issues.

[PatrickLee]

I love playing with modified cars, and oil standards directly affect performance: SAE grades like 5W-30 are thinner and better for acceleration compared to 10W-40, while API SP rating ensures strong high-temperature protection and wear resistance. ILSAC standards like GF-6 improve fuel efficiency and reduce operational resistance. High-performance engines prefer full synthetic oil, with stable viscosity that remains reliable even under extreme driving conditions. Choosing the wrong oil can lead to insufficient lubrication and premature engine aging, so always select the specified grade as per the owner's manual to prevent malfunctions. In high-temperature environments, the oil must be heat-resistant with minimal viscosity changes for smooth power output.

[AmaraLee]

I value environmental protection, and oil standards help reduce emissions: SAE viscosity such as 0W-20 reduces friction and saves fuel, while the new API SP standard decreases engine emission pollution. ILSAC grades like GF-6B promote green driving. Using the correct oil grade can extend vehicle life and reduce waste, with high-mileage oils protecting older vehicles from premature scrapping. In temperature-sensitive regions, choosing the right oil avoids excessive emissions, and recycling used oil is a key environmental practice.