Close Menu
  • Home
  • Engine Noise
  • Engine Overheat
  • Resources
  • Car Shut Off/Dies
  • About Car Care Site
    • Engine Oil
    • Disclaimer
    • Privacy Policy
    • Contact Us

Subscribe to Updates

Get the latest creative news from FooBar about art, design and business.

What's Hot

Why Is My Car’s AC Blowing Warm Air? Common Causes and Troubleshooting Tips

October 17, 2024

Why Your Engine Makes Ticking Sounds When Accelerating: Tips for Prevention and Maintenance

October 17, 2024

How to Fix Steering Wheel Vibration at Highway Speeds

October 17, 2024
Facebook X (Twitter) Instagram
CarCareSiteCarCareSite
  • Home
  • Engine Noise

    Why Does Misfire Happen When Starting A Car? Let’s Find Out!

    March 7, 2024

    Why Does Your Car’s Engine Misfire At Idle? Let’s Find Out!

    February 29, 2024

    What Causes Car Engine Misfire At Low RPM? Let’s Find Out!

    February 27, 2024

    Engine Misfire at High RPM? Diagnosis and Solution

    February 25, 2024

    Can a Bad Alternator Cause a Misfire?

    February 21, 2024
  • Engine Overheat

    Car Overheating Making Hissing Sound: Possible Reasons Why

    January 10, 2024

    Engine Overheating and Smoking: Understanding The Causes & Fixes

    December 31, 2023

    Car Overheats While Idling But Not Driving? Try This Solutions

    December 24, 2023

    Car Overheat When AC Is On? Here Is Why!

    December 20, 2023

    Car Overheats When AC Is Off? Try These Solutions!

    December 20, 2023
  • Resources

    Why Is My Car’s AC Blowing Warm Air? Common Causes and Troubleshooting Tips

    October 17, 2024

    Why Your Engine Makes Ticking Sounds When Accelerating: Tips for Prevention and Maintenance

    October 17, 2024

    How to Fix Steering Wheel Vibration at Highway Speeds

    October 17, 2024

    10W-40 vs 5W-40 Motor Oils: Choosing the Best Option for Your Engine

    October 17, 2024

    Why Do Brakes Squeak When Reversing: Causes & Solutions

    October 17, 2024
  • Car Shut Off/Dies

    Car Dies While Idling Alternator- Issues Explained

    December 18, 2023

    5 Reasons With Solutions for Car Shuts Off When Stopped Or Slowing Down

    December 18, 2023

    Car Dies While Driving But Restarts: 6 Common Causes & Possible Fixes

    December 18, 2023

    Car Dies After Removing Jumper Cables! Use These Fixes!

    December 16, 2023

    Why Car Dies While Driving And Cranks But Won’t Start?

    December 15, 2023
  • About Car Care Site
    • Engine Oil
    • Disclaimer
    • Privacy Policy
    • Contact Us
CarCareSiteCarCareSite
Home»Engine Oil»20w40 Vs. 20w50: Which Motor Oil Should You Choose?
Engine Oil

20w40 Vs. 20w50: Which Motor Oil Should You Choose?

Azim UddinBy Azim UddinDecember 14, 2023Updated:July 20, 2025No Comments6 Mins Read
blank
Share
Facebook Twitter LinkedIn Pinterest Email Copy Link

When it comes to selecting the best motor oil for your vehicle, the options can be overwhelming. The choice between 20w40 and 20w50 motor oils is a common dilemma for many vehicle owners.

So, what is the difference between 20w40 vs. 20w50? The 20w50 has a higher viscosity in warmer temperatures, making it suitable for high-performance engines. It is also efficient in older engines that require extra friction cushioning. Conversely, the 20w40 has a slightly lower viscosity in warmer temperatures and is best suited for standard engines.

This comprehensive guide will break down the differences between 20w40 and 20w50 motor oils. This will help you make an informed decision for your beloved vehicle.

Comparison Table: 20w40 vs. 20w50

Before we dive deep into the specifics, let’s start with a quick side-by-side comparison to give you an at-a-glance overview of 20w40 and 20w50 motor oils.

Property20w4020w50
ViscosityLess viscous in hot temperaturesMore viscous in hot temperatures
Hot Weather PerformanceLess suitable for very hot conditionsEffective in extreme heat
Flash Point200°C267°C
Pour Point-30°C-30°C
Fuel EconomyMore Fuel-EfficientSlightly Less Fuel-Efficient
Price (per 1L)$381$445
Where to UseLong-distance driving: it is more fuel-efficientGasoline and Diesel Engines (Moderate to Large), High-Performance Motorcycles, Aviation Vehicles, Older Vehicles

Overview Of 20w40 And 20w50

20w40 vs 20w50

Here is an analysis of the meaning of the numbers for both 20w40 and 20w50 motor oils.

What is 20w40?

20w40

Your 20w40 motor oil is specially formulated for various engine types and is often suitable for standard new engines. The “20w” in 20w40 represents the oil’s viscosity in cold temperatures. The W is a short form for winter.

Therefore, the 20 indicates that the oil has a low viscosity during winter. This aids in starting and lubrication in colder weather. This number is based on the SAE (Society of Automotive Engineers) classification.

The “40” part indicates that the oil has a moderate viscosity at high temperatures. It means that the oil provides adequate protection at higher temperatures without becoming too thin.

What is 20w50?

20w50

20W50 motor oil is typically used in older vehicle models. This is due to the fact that it protects and cushions the engine system against friction. As in 20w40, the “20W” part indicates how the oil flows at lower temperatures, particularly in colder weather.

Both 20w40 and 20w50 perform similarly in winter with a pour point of -30 degrees Celsius.

The “50” part indicates the oil’s viscosity at higher temperatures, such as when your engine is running hot. The higher number, like 50, indicates that the oil is thicker and has a higher viscosity. This helps maintain adequate lubrication and protection for the engine components.

To get the SAE class of both motor oils, they are passed through a viscometer at 100 degrees Celsius, which records the oil’s viscosity when it is hot. The 100 degrees Celsius mark represents the optimal working temperature of an engine.

Differences Between 20w40 And 20w50

The key differences and considerations between 20W-40 and 20W-50 oils are as follows:

Hot Temperature Performance

When it comes to hot temperature performance, the differences between 20W-40 and 20W-50 become more noticeable. 20W-50 oil is designed to perform better in high-temperature environments. This is made possible as it can handle temperatures of up to 267 degrees Celsius (flash point).

It retains its viscosity and lubricating properties even as the engine heats up to extreme temperatures. This makes it an excellent choice for hot climates or engines subjected to high revs and temperature conditions.

While 20W-40 performs well in high temperatures, it thins out slightly more than 20W-50. This becomes a problem in extremely hot environments or engines that generate a lot of heat.

Fuel Efficiency

The viscosity of motor oil also has an impact on fuel efficiency. Thicker oils have lower fuel efficiency because they require more energy to circulate within the engine due to their higher viscosity.

Conversely, 20W-40 oil is slightly thinner, which means it flows more smoothly and provides a slight advantage in terms of fuel efficiency. Note that other factors also play a significant role in determining fuel efficiency. These factors include driving habits, vehicle maintenance, and the engine’s overall condition,

Versatility

20W-40 oil is often considered a more versatile option because it falls in between the thinner oils like 10W-30 and the thicker oils like 20W-50. It is used in a wide range of engine types, including newer and older gasoline engines.

20W-50 oil is less versatile in comparison, as it is better suited for high-stress and high-temperature environments. This includes the hot climates and high-performance or older engines.

Price Difference

20W-40 is priced at $381 per liter, and 20W-50 is $445. The price difference demonstrates how the thicker 20W-50 oil is sometimes priced higher than the thinner 20W-40 oil.

Influence On RPM

Because 20W-50 oil is thicker at high temperatures, it reduces internal friction within the engine. Lower internal friction leads to smoother and more efficient engine operation. This allows the engine to rev more freely.

On the other hand, 20W-40 oil has a slightly lower viscosity at high temperatures. This causes slightly more internal friction within the engine, resulting in more resistance, making it unable to handle higher RPMs.

See: 20w40 vs 10w40: Which Viscosity is The Best for Your Engine in Winter?

Which One Is Right For You: 20W40 Or 20W50?

20W-50 oil is better suited for you if you are in an area with hot climates or you have either an old or a high-performance engine. It provides a thicker lubricating film at high temperatures, which can be beneficial for engines that run hot and require higher revving.

On the other hand, 20W-40 oil is a better choice for you if your vehicle has a standard engine. This is because its viscosity is suitable for normal driving conditions where you do not need high revs or engines that run hot. This, in turn, makes it more budget-friendly and more fuel-efficient.

See: 0w40 vs 5w40: Everything You Need to Know!

FAQs

Here are other related questions about 20w40 vs 20w50 motor oil you may want answers to.

Q1. Can 20w40 and 20w50 be used interchangeably?

You should not interchange them. Using the wrong oil can lead to engine wear and even potential damage. Stick to the recommended viscosity for your engine in your manual.

Q2. What does a multi-grade oil mean?

A multi-grade oil, also known as a multi-viscosity oil, refers to the oil having two distinct viscosities: one at low temperatures and another at high temperatures.

Conclusion

The choice between 20w40 vs. 20w50 motor oils is not merely a matter of numbers. It’s a decision that directly impacts the health and performance of your engine.

By understanding the significance of these numerical designations, you gain valuable insight into how these oils behave in both cold and hot conditions. 20w40 strikes a balance between being budget-friendly and fuel-efficient. This makes it a sensible choice if you own a vehicle with a standard engine. On the other hand, if your engine faces extreme temperatures, heavy usage, or you prioritize robust engine protection, 20w50 emerges as the preferred option. Always start by consulting your vehicle’s owner’s manual or contacting the manufacturer for their oil recommendations.

Share. Facebook Twitter Pinterest LinkedIn Tumblr Email
blank
Azim Uddin
  • Website
  • Facebook

Hi, I'm Azim Uddin, a student who loves cars. Visit carcaresite.com to learn about car maintenance for beginners and experts. In my studies, I found a cool connection between hosting and car care. Join me on this journey where every road has a story, and hospitality meets the thrill of cars. Explore, learn, and enjoy the ride with me!

Related Posts

15w40 vs 20w50: Head-to-Head Comparison

December 15, 2023

What Is The Difference Between 15w-50 Vs. 10w-40 Engine Oil?

December 15, 2023

15W50 VS. 20W50: What Is The Difference Between These Two Motor Oils?

December 14, 2023

Comments are closed.

Don't Miss
Engine Noise

Why Does Misfire Happen When Starting A Car? Let’s Find Out!

By Azim UddinMarch 7, 2024
Categories
  • Blog (268)
  • Car Shut Off/Dies (9)
  • Engine Noise (33)
  • Engine Oil (11)
  • Engine Overheat (10)
Latest Posts

Why Is My Car’s AC Blowing Warm Air? Common Causes and Troubleshooting Tips

October 17, 2024

Why Your Engine Makes Ticking Sounds When Accelerating: Tips for Prevention and Maintenance

October 17, 2024

How to Fix Steering Wheel Vibration at Highway Speeds

October 17, 2024

10W-40 vs 5W-40 Motor Oils: Choosing the Best Option for Your Engine

October 17, 2024
About Us

CarCareSite is your trusted guide for understanding and fixing everyday car problems—without the technical jargon. We focus on real-world issues like engine misfires, overheating, sudden shut-offs, shaking, and more. Our mission is to make auto care easy and accessible for everyone, whether you're a new driver or a seasoned DIY enthusiast.

We believe that car owners should feel confident about their vehicles. That’s why we provide simple, step-by-step articles to help you diagnose symptoms, understand causes, and find possible solutions. Our content is research-based, easy to follow, and focused on practical results—not just theory.

Our Picks

Why Is My Car’s AC Blowing Warm Air? Common Causes and Troubleshooting Tips

October 17, 2024

Why Your Engine Makes Ticking Sounds When Accelerating: Tips for Prevention and Maintenance

October 17, 2024

How to Fix Steering Wheel Vibration at Highway Speeds

October 17, 2024
Most Popular

Why Is My Car’s AC Blowing Warm Air? Common Causes and Troubleshooting Tips

October 17, 2024

Car Makes Whirring Noise When Slowing Down! 6 Causes and Their Fixes

September 18, 2023

Car Makes Intermittent Grinding Noise When Driving- 7 Reasons

September 18, 2023
  • Home
  • About Us
  • Contact Us
  • Disclaimer
  • Privacy Policy
Copyright © 2025 Carcaresite.com | All Rights Reserved.

Type above and press Enter to search. Press Esc to cancel.