Updated at: 09-03-2022 - By: micdot

If you’re having trouble finding the correct motor oil, it’s understandable. There are a lot of options out there when it comes to motor oil, so you may feel overwhelmed. Different viscosities can be found in a variety of motor oils. As a rule of thumb, the more viscosity a fluid has, the easier it is for it to flow through the engine. It will be easy to flow if the viscosity is low. Having motor oil that reaches all the way to the bottom of your engine is essential for high-performance engines to ensure appropriate lubrication.

Using heavier oil may be necessary if your vehicle is older and has a high mileage engine. Things like this should be familiar to drivers of automobiles. 15w40 motor oil and 10w30 motor oil will now be discussed. Whether or not these motor oils may be used interchangeably will be the subject of our discussion. Let’s get this party started..

What Is the Difference Between 15w40 and 10w30 Oil?

There are some similarities between the 10w30 and 15w40 motor oils. On the other hand, there are some variances between the two. Examine their differences in terms of fuel efficiency, heat, viscosity, and performance to discover more.

Viscosity

There are benefits to using 15w40 motor oil. In addition, it shields your engine from damage caused by severe temperatures. Heavy towing and bad roads are included in this. Using 15w40 motor oil in the winter will make the oil flow like a fifteen-weight oil. At full working temperature, it shields the 40-pound payload from damage.

Motor oil with a viscosity rating of 10w30 while the engine is cold is referred to as 10w30 motor oil. When the engine gets hot, the temperature rises to thirty degrees.

Fuel Economy

The soot, acid, and wear-prevention additives in your engine’s base oil are what keep it running smoothly. 15w40 is thicker than 10w30, but thinner than 15w40. Because of this, it has a lesser film strength. It’s also more likely to oxidize than other materials.

Motor oil with a 10w30 rating requires high-quality additives. A 10w30 motor oil, on the other hand, will outperform a 15w40 industry norm. Since viscosity changes while comparing the fuel economy of different weights of 15w40 and 10w30 motor oil, there is no one right solution. This is due to the fact that 15w40 motor oil has a wide range of viscosity. The 10w30 motor oil, on the other hand, is a synthetic base oil that is heat resistant and has low volatility and good viscosity stability. It is also highly resistant to oxidation. Engine top-off intervals will be extended as a result of this change. The assurance that your car won’t break down at any time will give you a sense of security. The 15w40 motor oil will provide you with the level of equipment protection you need. It will extend the life of your engine as well.

Hot Weather

10w30 is a multi-grade motor oil. Because it can endure high temperatures for an extended period of time, this motor oil is ideal for heavy-load engines. This is accomplished without affecting engine performance in any way.

 Ten is the viscosity rating for this motor oil in cold temperatures. The viscosity increases to a grade of 30 at high temperatures. As a result, at low temperatures, this motor oil has a low viscosity. In other words, this motor oil has a low melting point. 10w30 motor oil can also be used for sludge control. There is a breakdown in the sludge and gel formation at high temperatures. The 15w40 motor oil has a stronger oxidation resistance than other motor oils. High-temperature deterioration is also well-protected by this material’s outstanding resistance. It is possible to keep the viscosity of the 15w40 motor oil under control even at high temperatures. The 15w40 motor oil, on the other hand, minimizes the number of oil breaks in really cold temperatures.

Performance

Specific qualities and advantages of the 10w30 motor oil are numerous. Coatings of motor oil will be deposited on the engine’s various parts. As a result, the friction between them will be reduced. As a bonus, it will help keep your engine cool and save wear and tear. It is recommended that you use 10w30 motor oil to keep your engine’s components corrosion-free. This motor oil will help extend the life of your vehicle’s engine.

Drivers will appreciate the smooth and quiet gear and clutch shifts. Even at extremely high temperatures, the viscosity of this motor oil remains unaffected. Biodiesel and biofuel engines will greatly benefit from this motor oil, which is highly recommended. The 10w30 motor oil is suitable for usage in both cold and hot weather conditions. The 15w40 motor oil is a high-performance motor oil. Synthetic plus heavy-duty engine oil is also included.

Can I Use 15w40 Instead of 10w30?

But it doesn’t necessarily indicate that you should do so. 15w40 is thicker than 10w30, but thinner than 15w40. Another consideration is to use only the motor oil that your engine manufacturer recommends.

Instead of using 10w30 motor oil, you can swap it out for 15w40. However, this is not advisable. If you can, avoid using the preferred motor oil advised in your owner’s handbook by your vehicle’s manufacturer.

Accidentally Used 15w40 Instead of 10w30: Is It Ok?

Yes, it’s fine in the sense that your automobiles won’t be harmed. But that doesn’t mean you should go out of your way to do it. There will be no harm to your car if you unintentionally use 15w40 motor oil instead of 10w30 motor oil, and you can always perform an oil change if you like.

15w40 vs 10w30 High Mileage

This oil is suitable for engines with a high mileage. A 10w30 motor oil, on the other hand, is recommended for vehicles with heavy mileage. It’s made up of a blend of synthetic high-performance bases and additives that’s been carefully matched.

Which Is Better, 15w40 or 10w30 Oil?

15w40 is thicker than 10w30, but thinner than 15w40. As a result, the film’s strength is reduced, making it more susceptible to oxidation. It is still possible to use a high-quality 10w30 motor oil, which is better than the industry standard 15w40 motor oils.

The 10w30 motor oil, however, is not necessarily better for all of your automobiles. As a general rule, the best and most effective motor oil for your vehicle is that which your manufacturer recommends.

When Should I Use 15w40 And When 10w30?

Diesel trucks, farm tractors, personal vehicles, and many more can all benefit from the use of 15w40 motor oil. 10w30 motor oil is compatible with most automobile gasoline and diesel engines.

In hot conditions, this is a far superior engine oil to use. So if your owner’s handbook recommends 15w40 or 10w30 motor oil, you should use it.

15w40 vs. 10w30 Toyota

All Toyota engines should be lubricated with 5w30 motor oil. You can still use 15w40 and 10w30 motor oils, even though they aren’t on the list of approved brands. To reiterate, this isn’t anything we’d suggest you try.

Diesel engines may run on 15w40 motor oil. You can use the 10w30 motor oil in hot weather. However, your owner’s handbook is still your best bet.

15w40 vs. 10w30 Nissan

5w30 and 10w30 are the recommended motor oils for Nissan automobiles. 15w40 motor oil isn’t suggested, but if you want to, it’s fine.

Keep in mind, however, that doing so is not advised. Diesel engines may run on 15w40 motor oil.

15w40 vs 10w30 Subaru

All Subaru engines should be lubricated with 0w20 or 5w30 motor oil. You can use the 15w40 and 10w30 motor oils even if they are not on the list of recommended oils. To reiterate, this isn’t anything we’d suggest you try.

Diesel engines may run on 15w40 motor oil. You can use the 10w30 motor oil in hot weather. The recommended motor oil can still be found in your owner’s manual.

15w40 vs. 10w30 Mazda

Mazda’s cars and SUVs almost universally require 0w20 oil. Although 15w40 and 10w30 motor oils aren’t on the list of suggested products, you’re free to use them nonetheless. To reiterate, this isn’t anything we’d suggest you try.

Diesel engines may run on 15w40 motor oil. You can use the 10w30 motor oil in hot weather. However, your owner’s handbook is still your best bet.

15w40 vs 10w30 BMW

BMW recommends 5w30 oil for all of its engines. But if you choose, you can still use the 15w40 and 10w30 motor oils, which are not on the suggested list.

To reiterate, this isn’t anything we’d suggest you try. Diesel engines may run on 15w40 motor oil. You can use the 10w30 motor oil in hot weather.

15w40 vs 10w30 Ford

Ford’s 2020 owner’s manual specifies that a 5w30 motor oil or a 0w30 motor oil must be used in nearly all of their engines. It’s not suggested, but you can still use 15W40 and 10W30 motor oils if that’s what works best for your vehicle. To reiterate, this isn’t anything we’d suggest you try.

Diesel engines may run on 15w40 motor oil. You can use the 10w30 motor oil in hot weather.

15w40 vs 10w30 Chevrolet

Some engines in the Chevrolet lineup require 5w20, 5w30, or even 10w30 oil, depending on the model. 15w40 motor oil isn’t suggested, but if you want to, it’s fine.

Keep in mind, however, that doing so is not advised. Diesel engines may run on 15w40 motor oil. However, your owner’s handbook is still your best bet.

15w40 vs. 10w30 Jeep

Jeep vehicles should be lubricated with 0W20, 5W20, 5W30, or 10W30 viscosity oil. 15w40 motor oil isn’t suggested, but if you want to, it’s fine.

Keep in mind, however, that doing so is not advised. Diesel engines may run on 15w40 motor oil.

15w40 vs. 10w30 Volkswagen

Those are the only two intervals they recommend: 5 weeks (30 weeks) and 20 weeks (0 weeks). But even if you don’t want to, you can still use the 15w40 motor oil and 10w30 motor oil. To reiterate, this isn’t anything we’d suggest you try.

Diesel engines may run on 15w40 motor oil. You can use the 10w30 motor oil in hot weather. The recommended motor oil can still be found in your owner’s manual.

Summary

In general, 15w40 motor oil and 10w30 motor oil are interchangeable and can be used interchangeably. The greatest rule of thumb is to always adhere to the recommendations found in your vehicle’s owner’s manual.

It’s important to follow the manufacturer’s recommendations when it comes to oil for your car. Because they made the car, they know what kind of oil is best for it.