5w30 vs. 10w30 Review: The Last One You’ll Ever Need

5w30 vs. 10w30

You’re here in this section, so I’m assuming you’re also confused with the 5w30 vs. 10w30 battle. Thus here I’ll explain and review each of these types of engine oil.

What is the difference between 5w30 and 10w30? Which is better 5w30 or 10w30? Can you mix 5w30 with 10w30?

All these questions pop inside your head, so let’s get started.

Multigrade vs Monograde

Engine oils are, by and large, classified into two: multigrade and monograde.

Multigrade oil has two types of flows depending on the temperature or whether it’s warm or cold.

Monograde oil or single grade ones has, obviously, one type of flow.

This means that if you’re still driving in a place where temperature changes, the multigrade option is the way to go.

5w30 vs. 10w30: Difference

 Castrol 03084 EDGE 5W-30 Advanced Full Synthetic Motor Oil
Mobil Super 112917 10W-30 Synthetic Motor Oil

5w30 and 10w30 are both multigrade oil.

Multigrade oil has two numbers:

  • 1
    The first number, 5 and 10 before the W, is the equivalent weight at low temperatures like winter season;
  • 2
    The second number, 30, is the equivalent weight at operating temperatures.

 By the way, W means winter.

So as you can see, the main difference between 5W-30 and 10W-30 is the equivalent weight or thickness of the oil in cold temperatures as you start up.

Furthermore, another difference between these two oils is their cold-flow ability. A 10w30 oil will move slower than a 5w30 oil during cold startups.

What does this mean?

On a much simpler note, in cold climate places, it is highly recommended for you to use this type of oil to prevent your engine from wearing off. However, during operating temperatures, both oils will have just the same viscosity (30) and will flow and protect your car’s engine similarly.

Always bear in mind that if the oil will be in the engine during winter and you are in a place where it gets cold or where it’s always cold, use 5w30 oil. Now, if it’s summertime, use 10w30 for your engine.

But it is a different thing when you live in a tropical area for temperatures are consistently high and is least likely to get to near freezing, an even higher starting viscosity oil like 15w40 is highly recommended for you to use.

5w30 vs. 10w30: Which is Better?


10w30 is thicker than 5w30 which means that it will move slower when the temperature is still or when you’re in a place where the climate is relatively cold.

This is good because it means there’s less chance that the oil will “fly off of internal components when they’re in motion,” says Axle Advisor.

Thicker oil will also provide adequate lubrication of critical engine parts.

If you wish to enhance your old car’s engine performance level, thicker oil is also best for you to use. This is because oil passages in older vehicles are worn down making it more difficult for thinner oil to increase the oil pressure. When the oil pressure is low, oil won’t be pushed through all spaces that need lubrication.

In other words:

There’s no such thing as one being better over the other. It all depends on your engine’s needs.

In choosing between 5w30 and 10w30 motor oils, you must consider the following:

  • Temperature setting. This is the weather condition in your area or where you live for instance
  • The intended use. If you want to use your car in a cold climate place, choose 5w30 but use 10w30 for hot temperature and heavy-loaded vehicles.
  • The vehicle’s manufacturer’s recommendation. You should keep in mind to use the engine oil as assigned or advised to you by the vehicle’s manufacturer.

Is Thicker Oil Better than Thinner Oil?

5w30 vs. 10w30

Again, they are both great! You just have to remember that 5w30 oil type is the best choice for both high and low temperature, is highly efficient, and gives your engine the protection it needs.

In contrast, the 10w30 type is more viscous and will work better with cold climates and older vehicles.

So the best way to avoid mistakes in choosing the best oil for your car is to check your engine’s manual.

Now, for some cases like myself who sometimes is having a problem on what is written in the user manual due to some technical words that are hard to decipher, better consult your vehicle’s manufacturer if you are dealing with a brand new car.

In fact, don’t use oil that’s not recommended by your car’s manufacturer.

Engine Oil Codes Explained


Is Mixing Okay for 5w30 and 10w30?

If your car is using the usual multi-grade oil, like the 5W-30 or 10W-30, it is safe for you to use most any multi-grade oil you wish to “fill in” your oil and bring it up to its prior level.

Mixing the viscosity of oil does not affect the engine at all because 5W30 and 10W30 are most likely or is relatively close in thickness.

Can I Mix Oil with Different Viscosities?

Multigrade oil with a viscosity of 30 such as our examples above is thinner than a 10w40.

Which means the former will flow through your engine much faster than the latter.

Based on these facts, it is not advisable to mix these two as it may harm your car’s engine. This proposition is supported by NAPA or the National Automotive Parts Association.

What about Synthetic and Regular Oil?

Another question you may have is mixing the regular oil with a synthetic one. There are times when only one of them is available and you have to add one.

According to ThoughtCo, this is possible without harming your engine.

But be warned:

You are not to make this a habit. Although these two types have similar ingredients, they are made for different purposes.

The additives on the synthetic oil are for high temperature and pressure.

So mixing them regularly may force you to have an oil change more often than the average and damage your vehicle in the long run.

How to Change Your Oil (Complete Guide)



  • 5w30 is a perfect choice if you are living in the tropics.
  • For single grade oils, the lower the number, the better it flows at cold temperatures. Same goes with, the higher the number, the thicker the oil.
  • 5w30 vs. 10w30 means these two can both perform or are designed for cold starting temperature to normal temperature without sacrificing the performance of your engine upon startups.
  • telegram
    Engine or motor oils are mainly “lubricants.”  It ensures that the moving engine parts do not collide or touch with each other. If your engine does not have enough lubricant, the parts will most likely stop working and will inevitably be damaged. When this occurs, you must seek assistance or consult with a mechanic for a repair,  reconstruction or if damaged entirely, you may ask for a replacement for your engine which will cost you a good fortune.


In choosing the best oil for our engine, we all want what is highly efficient and economical at the same time. There’s really no such thing as one being better over the other.

However, we can’t choose just economical at all times.

The factors to consider in choosing the best oil for your engine are:

  • The weight of oil recommended by your vehicle’s manufacturer to give your engine of its utmost protection and be at its maximum fuel economy
  • The age of your car and most especially the temperature in your area
  • The oil that best suits the climate in your place

When using an old car, keep in consideration the type of oil that is much thicker to have your vehicle perform at its maximum capability.

Also, be careful when combining oils with varying viscosities as it may damage your car inadvertently.

When in doubt, always ask your manufacturer to be sure.

What points did we miss?

Please feel free to add your comments, suggestions, and recommendations here. Don’t forget to share this post as well. You may also ask questions for clarifications.

Related Tips and Tricks from TopPicksforHer Lists:

Leave a Reply

Your email address will not be published. Required fields are marked *