Updated at: 10-03-2022 - By: micdot

Your car’s engine relies on the use of motor oil. The oil in your engine is like the lifeblood of your vehicle. You need to choose the proper motor oil for your vehicle in order to avoid future engine damage and failure.

The viscosity of each motor oil also has a role. Viscosity is a requirement for any engine. You have a responsibility as a car owner to educate yourself on the proper type of oil to use in your vehicle. As a result, we’ll now discuss 10w40 and 15w40 motor oils. Whether or not you can use both 10w40 and 15w40 motor oil is the subject of this article. Let’s get this party started now.

What Is the Difference Between 10w40 and 15w40 Oil?

The viscosity of the oil has a role in the unique properties of each oil. Different types of 15w40 can be used according on the type of vehicle and location. We need to know how 10w40 and 15w40 motor oils differ when it comes to fuel economy, hot weather, and viscosity.

Viscosity

In cold and operating conditions, the motor oil grade refers to the weight of the motor oil. This is due to the fact that when temperatures rise, so does the viscosity of motor oils.

A 10w40 motor oil thickens more in cold conditions, for example, than a 15w40 motor oil. High-temperature viscosity is the same for both of them.

Fuel Economy

In comparison to a 15w40 motor oil, a 10w40 oil is believed to degrade more quickly. This is because the viscosity indexes of 10w40 motor oil are higher. However, this statement is regarded to be false.

This is the bane of today’s engines, as it drastically shortens their lifespans. Some sludges will also be present. There is a lack of data about the vehicle’s fuel efficiency. Because the vehicle is brand new and the weather is cold, we recommend 15w40 oil. To get the most out of your engine’s fuel economy, you need to use the manufacturer’s suggested motor oil.

Hot Weather

You can use 15w40 motor oil in both hot and cold conditions with no problems. When you see “Fifteen” in the motor oil label, it does not suggest that the temperature will be limited to fifteen degrees Fahrenheit at all times. There is a direct correlation between a lower first number and a lower second number. The oil will also be lubricated by more fluid. It’s best to use a heavier oil in the winter. The optimum motor oil to use is 15w40.

Can I Use 10w40 Instead of 15w40?

Many factors come into play here. Even though your manufacturer recommends 15w40 motor oil, you can use 10w40 instead, but you must be aware of this. The cold start performance will be reflected in the winter viscosity.

Static friction in an engine can be reduced by using motor oil with a lower number. As a result, 10w40 motor oil performs significantly better than 15w40 motor oil when starting from a cold stop. If the temperature drops, the 10w40 motor oil will thicken more than the 5w40 motor oil.

Accidentally Used 10w40 Instead of 15w40: Is It Ok?

At a temperature of 100 degrees Celsius, the viscosity of fifty-grade oil is significantly higher than that of forty-grade oil. As a result, at low temperatures, 15w40 motor oil will be thicker than 10w40 motor oil. As a result, it will have a considerably worse start-up flow. 15w40 motor oil is suitable for diesel vehicles, farm tractors, passenger cars and other machinery. ” Use the suggested motor oil for your vehicle as a general guideline.

10w40 vs 15w40 High Mileage

A 10w40 motor oil should be used in vehicles with a lot of miles on the clock. To help older engines withstand high temperatures, thicker oils are needed, such as 10w40 motor oil, which is more aggressive. If the motor oil is thicker, it will help extend the life of your engine by reducing wear and tear. If your car has been on the road for more than sixty thousand (60,000) miles, you should use 10w50 motor oil.

Which Is Better, 10w40 or 15w40 Oil?

There are a few variables to consider here. To begin, you need to think about the vehicle you’re driving and the weather circumstances. For the second time, the optimum motor oil for your engine is the one recommended by your manufacturer.

When Should I Use 10w40 And When 15w40?

If the temperature is above 90 degrees Fahrenheit when driving, you can use the 10w40 engine oil. The 10w40 motor oil is capable of operating in temperatures up to 104 degrees Fahrenheit. The maximum working temperature of 10w30 motor oil, on the other hand, is 85 degrees Fahrenheit. Even so, it’s always a good idea to consult the manual that came with your vehicle.

10w40 vs. 15w40 Toyota

All Toyota engines should be oiled using 5w30 motor oil, which is the industry standard. The 10w40 and 15w40 motor oils, on the other hand, are not on Toyota’s list of recommended motor oils. Use 10w40 engine oil if you’re driving in temps above 90 degrees Fahrenheit. You can use 15w40 motor oil if your car is brand new and has a cold location.

10w40 vs. 15w40 Nissan

Nissan automobiles should be lubricated with 5w30 or 10w30 synthetic motor oil. The 10w40 and 15w40 motor oils, on the other hand, are not on Toyota’s list of recommended motor oils. Use 10w40 engine oil if you’re driving in temps above 90 degrees Fahrenheit. You can use 15w40 motor oil if your car is brand new and has a cold location. Even so, it’s always a good idea to consult the manual that came with your vehicle.

10w40 vs. 15w40 Subaru

0w20 and 5w30 synthetic motor oil are the recommended lubricants for Subaru engines of all types. The 10w40 and 15w40 motor oils, on the other hand, are not on Toyota’s list of recommended motor oils.

Use 10w40 engine oil if you’re driving in temps above 90 degrees Fahrenheit. You can use 15w40 motor oil if your car is brand new and has a cold location.

10w40 vs. 15w40 Mazda

0w20 engine oil is required for nearly all Mazda cars and SUVs. The 10w40 and 15w40 motor oils, on the other hand, are not on Toyota’s recommended list of motor oils.

Use 10w40 engine oil if you’re driving in temps above 90 degrees Fahrenheit. You can use 15w40 motor oil if your car is brand new and has a cold location. However, the correct engine oil should be found in your vehicle’s owner’s manual.

10w40 vs. 15w40 BMW

They recommend 5w30 motor oil for all BMW engines. The 10w40 and 15w40 motor oils, on the other hand, are not on Toyota’s list of recommended motor oils.

Use 10w40 engine oil if you’re driving in temps above 90 degrees Fahrenheit. You can use 15w40 motor oil if your car is brand new and has a cold location. Even so, it’s always a good idea to consult the manual that came with your vehicle.

10w40 vs. 15w40 Ford

Most Ford engines require a 5w30 or 0w30 motor oil, according to the owner’s manual for the 2020 model year. Toyota does not advocate using 10w40 or 15w40 motor oils in its engines, respectively.

Use 10w40 engine oil if you’re driving in temps above 90 degrees Fahrenheit. You can use 15w40 motor oil if your car is brand new and has a cold location.

10w40 vs 15w40 Chevrolet

In some Chevrolet engines, 5w20, 5w30, or 10w30 is the recommended oil. The 10w40 and 15w40 motor oils, on the other hand, are not on Toyota’s list of recommended motor oils.

Use 10w40 engine oil if you’re driving in temps above 90 degrees Fahrenheit. You can use 15w40 motor oil if your car is brand new and has a cold location. However, the correct engine oil should be found in your vehicle’s owner’s manual.

10w40 vs. 15w40 Jeep

Jeep vehicles should be lubricated with 0W20, 5W20, 5W30, or 10W30 viscosity oil. Toyota does not advocate using 10w40 or 15w40 motor oils in its engines, respectively.

Use 10w40 engine oil if you’re driving in temps above 90 degrees Fahrenheit. You can use 15w40 motor oil if your car is brand new and has a cold location. Even so, it’s always a good idea to consult the manual that came with your vehicle.

10w40 vs. 15w40 Volkswagen

Only 5w30 and 0w20 are recommended by them. Toyota does not advocate using 10w40 or 15w40 motor oils in its engines, respectively. Use 10w40 engine oil if you’re driving in temps above 90 degrees Fahrenheit. You can use 15w40 motor oil if your car is brand new and has a cold location. However, the correct engine oil should be found in your vehicle’s owner’s manual.

Summary

Choosing the correct motor oil for your vehicle’s engine is essential to its long-term health. Even if you have engine oil, it is critical that you use the correct viscosity and type of oil.

You must consult your owner’s handbook to determine the correct motor oil for your vehicle. They’re the ones who can tell you what kind of oil your car needs.