Differences between 0w40 and 5w40

Engine oil is an essential component for any vehicle’s performance and longevity. The oil helps to lubricate the moving parts of the engine, prevent wear and tear, and reduce friction. When it comes to selecting the right oil, there are several options available, each with its own properties and advantages. Two common types of engine oil are 0w40 and 5w40, which have some key differences.

Differences between 0w40 and 5w40:

  1. Viscosity at cold temperature The first and most significant difference between 0w40 and 5w40 is their viscosity at cold temperatures. The “w” in the oil’s name stands for winter, and it indicates the oil’s cold temperature viscosity rating. 0w40 oil has a lower viscosity at cold temperatures than 5w40, making it more suitable for use in colder climates. In contrast, 5w40 oil has a slightly higher viscosity at cold temperatures, making it better suited for use in warmer climates.
  2. Viscosity at operating temperature Both 0w40 and 5w40 have the same viscosity rating at operating temperatures. This means that the oils have the same level of thickness when the engine is running, regardless of the type of oil used.
  3. Fuel economy Due to its lower viscosity, 0w40 oil is generally considered to be more fuel-efficient than 5w40. The lower viscosity allows the oil to flow more freely, reducing friction and improving engine efficiency. This can lead to improved fuel economy, which is an important consideration for many vehicle owners.
  4. Performance in extreme conditions Both 0w40 and 5w40 oils are designed to perform well in extreme conditions, such as high temperatures and heavy loads. However, 0w40 oil may be better suited for use in extreme cold conditions due to its lower viscosity at low temperatures. In contrast, 5w40 oil may be better suited for use in extreme heat due to its slightly higher viscosity at operating temperatures.


In summary, the main differences between 0w40 and 5w40 are their viscosity ratings at cold temperatures and their fuel economy. 0w40 oil is generally better suited for use in colder climates and may provide better fuel efficiency, while 5w40 oil may be better suited for use in warmer climates and extreme heat. It is important to consult your vehicle’s owner manual and consider your driving conditions before selecting an engine oil.

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