What does the model number of car engine oil represent?

[Joann]

The model number of car engine oil represents: indicators of low-temperature fluidity and high-temperature resistance. The method for changing the engine oil is: 1. Lift the car, remove the protective plate, and place a container under the oil drain screw; 2. Unscrew the oil drain screw, use an air gun to blow for two minutes at the oil filler port, after draining, tighten the oil drain screw and wipe it with a tissue to check for oil leaks; 3. Reinstall the protective plate and lower the car, then add engine oil at the oil filler port. The functions of engine oil are: lubrication and anti-wear, auxiliary cooling, cleaning, sealing and leak prevention, rust and corrosion prevention, and shock absorption. Its classifications include: 1. Ordinary mineral oil; 2. Semi-synthetic oil; 3. Fully synthetic oil.

[DelMary]

The combination of numbers and letters in motor oil grades, such as 5W-30, actually represents the oil's viscosity and temperature adaptability. The number before the W indicates cold temperature performance—the smaller the number, the better. For example, 5W can flow smoothly at startup in temperatures as low as -30°C. The number after (30 in this case) represents high-temperature viscosity, with higher numbers indicating thicker oil at high temperatures for better engine protection. I learned this the hard way with my old car when I used the wrong 10W-40 grade—it was difficult to start on winter mornings, and fuel consumption increased. After consulting the manual and switching to 5W-30, the car ran much smoother. These grades are also related to API service levels, like SP which represents newer standards with better environmental protection and durability. Choosing the right oil is no trivial matter—it affects engine wear, fuel consumption, and even emissions. Always follow the manual's recommendations rather than buying blindly, as you may need to adjust the grade between summer and winter. Regularly check the dipstick; if the oil appears black, it's time for a change. This simple habit can save you significant repair costs.

[SanAmir]

As a frequent car repairer, I see that the key to oil specifications lies in helping customers choose the right viscosity. The number after 'W,' such as 40, indicates high viscosity at high temperatures, suitable for protecting older engines; the number before 'W,' like 0W, means smooth starting even in the coldest weather. API classifications like SN or SP denote quality and anti-wear performance upgrades. I once encountered a car owner using the wrong type, which caused piston overheating issues. After switching to the correct 5W-30, the engine noise disappeared. Mismatched specifications can lead to oil film rupture, increasing wear, and may shorten oil life. It's best to refer to the vehicle manual recommendations rather than just trusting advertisements; for modified cars or high-temperature areas, choose a type with a higher high-temperature number to enhance performance, which can save on repair costs. Regular oil changes are crucial—check every 5,000 kilometers.

[JourneyDella]

Engine oil grades represent temperature and performance compatibility. A lower number before W, such as 0W, indicates smoother cold starts, while the following numbers like 30 or 40 correspond to high-temperature protection capability. Higher API levels like SN to SP enhance protective properties and cleaning efficiency. Improper selection can increase fuel consumption and emissions, harming environmental protection. Following the manual optimizes fuel efficiency and reduces waste.