5w30 vs 10w30: Which is Better For Your Car

Engine oil is a vital element in running the engine of a vehicle. It provides lubrication between moving parts that operate the engine. This prevents friction that leads to wear and tear. Engine oil also acts a coolant especially when engines are operating in higher temperatures.

There are many types of Engine oils based on their viscosity grades. We have 5w30, 10w30 or 10w40. According to Society of Automotive Engineers (SAE), viscosity grades are measured from the lowest (for cold conditions) to the highest (hot) grades.

The low grade means the engine oil can flow in cold temperatures effectively. In contrast, high-grade viscosity operates in hot temperatures. 5w30 is a low viscosity grade while 10w40 the highest.

Important Note;

The letter 'W 'means winter. However, many confuse it with the word 'weight'. The higher the number in W, the less effective the engine oil is during winter and vice versa.



A simulation of liquids with different viscosities. The liquid on the left has lower viscosity than the liquid on the right. via: wikipedia.org

Viscosity is the thickness of a fluid (in our case engine oil). In the engine oil, the viscosity is maintained at different temperatures. It is measured at 210F. This represents the engine temperature at normal operation.

High -Mileage Grade Oil

This is a type of oil that has distinctive additives that operates the engine effectively on longer period without strain.This type of oil is convenient for older engines. 10w30 is one example of high mileage grade oil.

5w30 and 10w30​

5w30 and 10w30 are the most popular engine oils used. We shall discuss them in detail and also their differences.

What's 5w30?

First of all, this is a type of thin grade engine oil used in a vehicle engine operating in cooler weather conditions (like winter). This is specified in the number '5'. Five is the number representing the lowest oil viscosity level.

At 5, the oil is thinner which means, it will flow effectively even when the temperature is very low. The number 30 is the thickness of oil at high temperature. So, if you are looking for engine oil that will service your vehicle in winter period, choose 5w30.

Interestingly, you can still use 5w30 in warm summers (though 10w30 is the best recommendation for hot summers). 5w30 is best suited if you are driving in northern parts of US and Canada. These areas experience low temperatures during winter periods.​

What about 10w30?​

10w30 is high -mileage grade engine oil. As the number indicates (10), it is normally used in warmer temperatures (suitably hot summers). 10w30 flows effectively in high temperatures because the viscosity has been made to flow effectively in that condition. How is it done?

Additives called 'viscosity improvers' are used to expand and contrast it. The thickness (30) is the same as that of 5w30. The thickness offers full protection to the engine when the temperature rises or falls. This type of oil is good for your engine vehicle when driving in California or Nevada (more so in the desert areas).

5w30 vs 10w30 - What's The Difference?

  • 5w30 engine oil is suitable for winter conditions because of the thin viscosity at low temperature compared to 10w30.
  • 10w30 will give your engine great service during the hot summer periods compared to 5w30.
  • If you don't want to be disappointed during winter, then 5w30 is the best oil for engine startup.
  • 10w30 is the best option for heavy load engines due to its ability to withstand hot temperatures for long period. A 5w30 will create a problem if used by heavy duty engine.​
  • 10w30 is suited well for buses and taxis that stop and go frequently as compared to 5w30.​

As we have seen, 5w30 appears to be the best solution for winter weather. Also, you can still use it in summer weather. However, if the vehicle engine operates on a longer period especially in hot summertime, it will be wise you use 10w30. You can also use 10w30 for older engine vehicle that needs more viscosity for better protection as compared to newer ones.

Final Verdict

In conclusion, it is highly recommended to use the right engine oil in line with the frequency of the engine usage and weather conditions. We don't want to have a vehicle that consumes more fuel due to engine constraint. If you are in the United States, I recommend, when buying engine oil, to look for API 'starburst' symbol. API stands for American Petroleum Institute.

The organization periodically checks engine oil manufacturers to meet prescribed standards. That means more money being spent. Lastly, it is wise if you follow the vehicle's engine manual to better understand the right engine oil to use.​

​Just like cleansing your blood to make run body functions effectively, the same is applied for engine oil in a vehicle. Therefore, use the right engine oil and best of luck!

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