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.
