The Meaning of Motor Oil Specifications
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In motor oil specifications, the "W" stands for WINTER. The number before "W" indicates the oil's viscosity at low temperatures. A smaller number means better low-temperature fluidity, providing superior engine protection during cold starts. The number after "W" represents the oil's viscosity at 100°C - higher numbers indicate higher viscosity and better high-temperature engine protection. Motor Oil Introduction: Motor oil, also known as engine lubricant, is often called the "blood" of a vehicle. It performs multiple functions including lubrication, cleaning, cooling, sealing, wear reduction, rust prevention, and corrosion protection. Motor oil consists of two components: base oil and additives. The base oil is the primary constituent that determines the fundamental properties of the lubricant, while additives compensate for and improve any deficiencies in the base oil's performance, providing additional beneficial characteristics. Motor Oil Classification: Motor oils on the market can be broadly categorized into mineral oils and synthetic oils based on their base oil composition (vegetable oils are excluded due to limited production). Synthetic oils are further divided into full synthetic and semi-synthetic types.
Those number combinations in oil grades are quite meaningful. Having driven for over a decade, I know you need to pay attention to these codes. Take 5W-30 for example - the 5W indicates good fluidity at low temperatures (W stands for winter), making engine starts easier in cold weather and ensuring rapid lubrication of components upon ignition. The 30 represents viscosity at high temperatures, maintaining robust protection when the engine runs hot to prevent excessive metal wear. Choosing the wrong grade can cause hard starts and loud noises in older vehicles, while newer cars may experience poor fuel efficiency and weak performance. I remember a friend once used 20W-50 during winter - the engine rattled terribly until switching to 5W-30 fixed it immediately. For routine maintenance, always select oil according to your owner's manual recommendations rather than buying randomly. Engine longevity depends on this! Also remember to check oil levels more frequently during hot summer operation.
Engine oil grades are set based on international standards. For example, in 5W-30, the 5 indicates the low-temperature viscosity grade, 30 represents high-temperature viscosity, and W stands for winter. Good low-temperature fluidity reduces friction damage during engine startup, while high high-temperature viscosity prevents oil thinning and component wear. Choosing the correct grade can improve fuel efficiency by approximately 10% and avoid frequent repairs. As someone who pays close attention to vehicle details, I know that long-term use of incorrect oil may lead to sludge buildup or increased fuel consumption, affecting overall performance. It is recommended to check the oil condition every five thousand kilometers and choose between full synthetic or semi-synthetic oil types based on the vehicle model and driving habits.
Nowadays, engine oil specifications have become much more complex than before. Back in my younger days, there were only two types: summer and winter. Modern engines are highly precise and require oils with specified temperature adaptation ranges to ensure stable operation between -30°C and 40°C. The significance lies in providing freeze and heat protection under any weather conditions. For daily use, adjusting according to regional climate is crucial. In colder northern regions, 5W-30 is suitable, while in hotter southern areas, 10W-40 can be chosen, extending engine lifespan by tens of thousands of kilometers. Regularly replacing the oil filter is a key complementary practice.
