How are motor oils classified?

[Mario]

Currently, the market classifies motor oils into three categories: mineral oils, semi-synthetic oils, and synthetic oils. Below are the locations and precautions for adding motor oil: Location for adding motor oil: Generally, motor oil should be added to the middle between the upper and lower limits on the dipstick. Try not to go below the middle, as high-speed driving can cause the engine to heat up, making the oil thinner. If the oil level is too low, it will reduce lubrication effectiveness. It's acceptable to have a bit more than the middle, but never exceed the upper limit on the dipstick, as this can cause significant damage to the engine. Precautions for adding motor oil: Motor oils used in cars generally contain detergents and dispersants that can clean off the carbon deposits and sludge adhering to the pistons and disperse them in the oil, reducing the formation of engine deposits. Therefore, after some use, the oil color may turn black, but this does not necessarily mean the oil has completely deteriorated.

[LaDelaney]

I once worked at an auto repair shop and learned that motor oil grades are primarily indicated by letters and numbers. The 'W' stands for winter viscosity, where a lower number before the W means better low-temperature fluidity, making cold starts easier. The number after the W represents high-temperature viscosity, with a higher number indicating more stable lubrication when hot. For example, 5W-30 is suitable for all-season use. Choosing the right grade protects the engine, reduces wear, and improves fuel efficiency. New standards like API's SP grade offer superior cleaning performance, but older cars might still perform well with lower grades like SN. I've seen many cases where using the wrong oil caused engine knocking, so I recommend consulting the owner's manual or a professional mechanic. Environmental factors also matter—use lower W numbers in cold climates and higher second numbers in hot climates, and change the oil regularly to keep the engine running smoothly.

[LaFelix]

As a car owner, I always pay attention to those label numbers when choosing engine oil. The grade refers to the SAE system, such as 0W-20 or 10W-40. The number before the W indicates low-temperature performance—lower numbers mean better cold-weather starting. The number after the W refers to high-temperature protection. Oils with higher second numbers resist thinning better in hot conditions. API grades like SM or SN indicate newer numbers represent stronger cleaning and anti-wear capabilities. The key is to select a matching grade based on the engine type—SUVs typically use thicker oil, while sedans use thinner. Don’t skimp and choose the wrong oil, or you may face increased engine noise and higher fuel consumption. I regularly check the dipstick and change the oil to ensure the car stays healthy, and maintenance records are also important.

[MacLila]

Engine oil grades are based on viscosity and performance standards. SAE numbers like 5W-30, where W stands for Winter, with lower numbers indicating smoother cold starts; higher high-temperature numbers represent stronger viscosity. API grades like SP denote high-performance versions. Always match the manual's recommendations when selecting—older vehicles use lower API grades, while newer ones require higher grades. Using the wrong grade accelerates engine wear, and I recommend checking oil quality every 5,000 kilometers.

[DelHailey]

After decades of driving, I've noticed significant changes in motor oil grades. Early oils were simple SAE 30, but now we have detailed classifications like 0W-16, which offer better low-temperature fluidity, fuel efficiency, and engine protection. API standards have also upgraded, with SP providing stronger cleaning capabilities than the older SM. When choosing oil, consider your region and season: use lower W numbers in cold areas and higher second numbers in hot regions. Never neglect regular oil changes, as they can extend engine life.

[SanMackenzie]

The oil classification system includes SAE viscosity grades and API performance standards. A lower number before the W in SAE indicates better cold-start performance, such as 5W; a higher number after it ensures lubrication at high temperatures. API ratings like SN denote modern protection capabilities. I choose oil based on vehicle age and environment—newer cars use thinner oil for efficiency, while older ones require thicker oil to prevent leaks. Advancing standards reflect technological progress, and regular maintenance is crucial.