Understanding the Difference between 5W40 and 15W40 Engine Oil

Proper vehicle maintenance is crucial to its longevity and performance. One key element for appropriate engine care is engine oil; with many different kinds available, it can be challenging to choose the most suitable choice. 

5w40 and 5w40 full synthetic oil  multigrade oils offer other properties and applications – we will explore their respective benefits and drawbacks in this article to help make an informed decision.

Overview of 5W40 Engine Oil

5w40 engine oil is a multigrade blend of synthetic crude oil and petroleum suitable for year-round use, featuring winter as its category name. It has two viscosities–one at lower temperatures (usually 150degC when running the engine) and the other at higher (typically 150degC when the engine is operating). This “W” indicates it should be winter-grade oil.

One of the primary advantages of 5w40 oil is its versatility: From temperatures as low as -30degC (-22degF) up to +40degC (104degF). In particular, this formula excels in hotter environments and should be considered an excellent option for vehicles driven around 15,000 miles annually.

Advantages of 5W40 Engine Oil:

5w40 oil provides excellent engine cleaning capabilities, helping maintain optimal health and lengthen engine lifespan.

Heat Resistance: This oil type boasts excellent heat resistance, helping protect engines against damage under high-temperature environments.

Performance under Extreme Conditions: 5w40 tires are engineered to efficiently handle aggressive driving styles and harsh environmental conditions, guaranteeing consistent performance.

Long-Lasting Properties: The oil retains its properties over an extended period, offering protection from engine wear.

Negative Aspects of 5w40 Engine Oil:

5w40 oil tends to be more costly than 15w40 in terms of cost.

Manufacturer Recommendations: While 5w40 oil may be suitable for specific engines, certain vehicle manufacturers do not necessarily advise using it in them.

Not for Worn Engines: This process may not be suitable for older engines that have sustained substantial wear.

Overview of 15W40 Engine Oil

15w40 diesel motor oil is another multigrade option that performs admirably in cold and warm temperatures. It features flowability at both low (with its “W” standing for winter) and high temperatures of 100degC or greater. The “15W” indicates its suitability at lower temperatures while “40″ indicates its performance at higher temps – typically around 100degC.

At 100degC, 15w40 has an ideal viscosity range from 12.5 to 16.2 mm2/s with cold resistance down to approximately -20degC (4degF), making it suitable for environments between -20degC and 40degC.

Advantages of 15w40 Engine Oil:

All-Season Use: 15w40 is suitable for use in cold and warm temperatures, making it versatile.

Ideal for Worn Engines: This cleaner works well on older, worn-out engines to prevent corrosion and remove sludge build-up.

Ideal for Hot Climates: 15w40 is explicitly designed to perform well in engines operating under hot temperatures.

Drawbacks of 15w40 Engine Oil:

Limitations at Extreme Cold Temperatures: 15w40 can handle moderately cold conditions but may not be ideal in subzero environments. 

Are 5w40 or 15w40 Oil Same?

While 5W-40 and 15W-40 are both multigrade engine oils and share similar names, they exhibit distinct differences in various aspects. The following table highlights the main contrasts between these two types of engine oils.

5w40 or 15w40: Which One Is Superior?

The choice between 5w40 and 15w40 depends on various usage conditions and needs. 5w40 excels in warmer climates, providing exceptional stability and protection even under adverse circumstances; 15w40, on the other hand, may perform better in colder regions as it maintains its properties even at subzero temperatures.

For optimal vehicle performance, it is vitally important that you follow the manufacturer’s recommendations when choosing oil for it. Departure from these guidelines could void your warranty.

Can I combine 15w40 with 5w40?

Although technically possible to mix 15w40 with 5w40 oils, it is not advised. Mixing oils may compromise performance and lead to unexpected issues with your vehicle. If mixing oils must occur regardless of warranty restrictions or otherwise be for whatever reason necessary, ensure compatibility before consulting a professional mechanic.

Conclusion

Choosing the ideal engine oil type – 5w40 or 15w40 – for your vehicle is critical to its optimal performance and longevity. When deciding, consider climate, manufacturer recommendations, vehicle needs, and specific characteristics. Opt for quality brands to ensure quality and reliability when choosing an oil type; by understanding their differences, you can make an informed choice that will keep your diesel engine running smoothly for many years ahead.