5w30 Vs 10w40 Engine Oil: Which Is Ideal For Your Car?

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Motor oils have different weights, and the difference in weight is for a reason. The reason is engine-specific; that is to say, auto engines are designed to use motor oils of different weights or viscosity.

If you found yourself contemplating between 5w30 vs 10w40 motor oils, here’s a detailed comparison of these two motor oils of different weights and viscosity.

5w30 oils are lighter than 10w40 oils, but they are recommended (each) for different situations.

On a quick note, you could actually use a different oil (not the recommended in your car’s owner’s manual) and nothing would happen to your engine – at least not that moment.

Basically, oil specifications by engine manufacturers are a “tradeoff,” your engine might even perform better with an oil type not recommended by your car engine maker.

What is a 5w30 Engine Oil?

5w30 Vs 10w40

5w30 implies that the specified oil has a thinner consistency in cold weather; however, it’d still perform the major function, which is to protect the engine at different temperatures, while also lubricating the moving parts to prevent friction.

But, a 5w30 would not offer the same protection as 10w40 because it is less thick at both high and low temps. 5w30 oils are specified for most modern engines, and while it’s really good, it is not preeminent to other oils.

If you live in a region or drive in cities with year-round low temps, using 5w30 may be the best option here. This is because a 5w30 oil would flow more easily in low temps than 10W30 or 10w40.

Related Posts: Can I Use 5w30 Instead Of 5w20 In My Honda?

What is a 10w40 Engine Oil?

10w40 means the oil would flow well in low temps and high temps; however, the flow would not be as swift as a 5w20 or 5w30 oil. But 10w40 oils have an added advantage; they typically offer more protection than lighter oils.

A 10w40 is a “thick” oil, and as such, it won’t flow too easily regardless of the temperature. This type of oil is often recommended for heavy-duty engines; cars that are used for “heavy-duty” tasks or driven in cities with high temp.

It is advisable to use a 10w40 oil if the temperature of your city is below 30 degrees Fahrenheit. This can cause damage to your engine because a 10w40 oil won’t be efficient and lubricate the engine moving parts as supposed at such low temps.

So, does this imply that what determines the oil to use for your car is the temperature of your city or state?

No, every manufacturer has a reason for specifying a particular type of oil for their various car models.

When you use the wrong oil for your engine, you’d likely notice a significant drop in performance, and over time, your engine or its components may start to break down.

5w30 Vs 10w40 Engine Oil: Which Is Best For You?

The truth is, you need to use the oil recommended for your engine by its maker if you want to get the best out of your engine. If the recommended oil is 5w30, stick to that; however, you may not use the exact recommended brand, and it’s okay.

In the same vein, if your engine is specified to use 10w40, it is advisable to stick with that. If the brand recommended by your OEM sells their 10w40 or 5w30 oil at a high price, it’s cool to find a cheaper universal equivalent of the same weight and specs.

Regardless, if you’ve been using 10w40 and wish to switch to 5w30, you must take into consideration how the temperature of your city could get so high or so low.


5w30 and 10w40 are both good depending on how your engine is designed and the temperature in your location.

Furthermore, it is important to point out that engine oils are made with different additives. Thus, some may perform better than the oil depending on the additives included in the formula.

When buying motor oils, it is good to consider options from top brands because they are typically made with OEM-approved, premium additives.

In summary, what you should know is that 5w30 oils are less viscous and flow easily than 10w40 oils at both high and low temps. Both oils are good for modern engines, and you can get them in different stores.

Related Posts: Can I Use 5w20 Instead Of 5w30 on Toyota?

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