Why do Japanese cars require low-viscosity engine oil?

[OIsaac]

The reason Japanese cars require low-viscosity engine oil is: The more precise the components, the less dependent they are on the viscosity of the engine oil. The functions of engine oil include: lubrication and wear reduction, auxiliary cooling, sealing and leak prevention, rust and corrosion prevention, and shock absorption. Engine oil is categorized into mineral oil, semi-synthetic oil, and fully synthetic oil. The method for changing engine oil is: 1. Lift the car, remove the undercover, and place a container of about 10 liters under the oil drain plug; 2. Unscrew the oil drain plug, use an air gun to blow for two minutes at the oil filler port, then tighten the oil drain plug after draining and wipe it with a tissue to check for leaks; 3. Reinstall the undercover and lower the car, then use a funnel to add engine oil through the oil filler port.

[AbelDella]

I usually enjoy keeping up with automotive knowledge and have noticed that Japanese cars generally recommend low-viscosity engine oil. This is mainly because their engines are designed with precision, featuring smaller gaps between components. Using high-viscosity oil can lead to less smooth lubrication, increased friction, and higher fuel consumption as the engine works harder. During cold starts in winter, low-viscosity oil flows more quickly, providing faster engine protection, reducing wear, and improving startup efficiency. Additionally, with the current emphasis on fuel efficiency and environmental protection, low-viscosity oil helps reduce engine resistance, allowing you to travel a few more kilometers per tank, saving money and being eco-friendly. From some forums, I’ve also learned that Japanese automakers have confirmed through testing that low-viscosity oil extends engine life, making it suitable for urban driving conditions with frequent starts and stops.

[SanOwen]

In my work, I frequently encounter Japanese car maintenance cases where owners opt for high-viscosity oil for convenience, only to experience increased engine noise and soaring fuel consumption. Japanese engines feature compact internal spaces with smaller clearances. Low-viscosity oil flows like a fine stream, ensuring more uniform lubrication that reduces component friction and wear. It also enables faster cold starts, minimizing hard-start damage. This aligns perfectly with manufacturers' optimized designs, delivering long-term maintenance savings. I've also observed that low-viscosity oil has appropriate change intervals at reasonable costs, preventing premature engine aging. Just remember to check oil levels diligently during maintenance.

[VonBennett]

I've driven quite a few older and newer cars. In the past, high-viscosity oil was the mainstream, but Japanese cars have switched to low-viscosity oil. The reason lies in the reduced weight of new engines and the precision of components, which are as fine as micro-carving. Low-viscosity oil penetrates and lubricates more easily, preventing jamming issues. It ensures quick cold starts and is safe and reliable. From a technical evolution perspective, this aligns with the trend of lightweight design, improving fuel economy and saving a significant amount on daily fuel expenses. Compared to American cars, the difference is quite noticeable, as Japanese cars place more emphasis on practicality and efficiency.

[Mila]

As an ordinary car owner, I've been using Japanese cars for many years. Following the advice to use low-viscosity oil, I've noticed smoother engine starts and reduced fuel consumption, saving a bit on gas each month. Low-viscosity oil provides efficient lubrication, protecting the engine and reducing wear, especially during cold seasons when it ensures quicker starts and a more reassuring drive. The reasons behind this include smaller engine clearances and material upgrades, making high-viscosity oil too thick for modern designs. Additionally, the push for environmental friendliness drives the need for fuel efficiency, and choosing the right oil can extend the vehicle's lifespan. Daily maintenance is simple, but don't overlook regular check-ups.