0W-20 vs 5W-20 Oil: Which One Should You Choose?

Confused about the 0W-20 vs 5W-20 oil debate?

Which one offers better fuel efficiency for your car’s engine?

While both are high-quality synthetic motor oils, they differ significantly in their viscosity rating, flash point, and other key aspects.

Let’s delve into the nitty-gritty of these two oils and understand which one’s more suitable for your engine. We’ll also address the most commonly asked questions about 0W-20 vs 5W-20 oil.

0W-20 vs 5W-20: What Are They?

0W-20 and 5W-20 are types of multi-grade oil with low viscosity and low pour point temperatures.

What does that mean?
Instead of thickening, these oils flow (or pour) more easily at low temperatures.

Now, let’s break down their acronyms.

The letter ‘W’ stands for ‘Winter,’ indicating that both oils are suitable for cold weather conditions. They help your cars achieve a better fuel economy by requiring less idling time.

The numbers indicate the viscosity or thickness of the engine oil.

The number before ‘W’ indicates the oil’s viscosity at a low temperature.
The second number after ‘W’ represents the oil’s viscosity at the engine’s operating temperature (or higher temperatures).

This means that the 0W20 oil has a viscosity rating of 0 in low temperatures and 20 at the engine’s normal operating temperature. Similarly, the 5W20 oil has a viscosity rating of 5 at a cold temperature and 20 at the engine’s normal operating temperature.

Important: Engine oil with low viscosity flows easily at a low temperature, whereas a higher viscosity oil is thicker and flows slowly.

Given their different viscosity ratings, which is more likely to enhance engine performance during a cold start?

How to Choose Between 0W-20 vs 5W-20 Oil

Determine the right choice of multi-grade oil for engine protection based on these factors:

1. Viscosity

Viscosity measures an oil’s resistance to flow at different temperature settings.

The 5W-20 oil has a slightly higher viscosity at a cold temperature than 0W-20. Hence, the latter flows more easily and reaches critical engine parts faster in cold weather.

However, both operate similarly at the engine’s operating temperature or higher temperatures.

2. Climate

0W-20 oil is suitable for extremely cold places with below-freezing conditions, with the low and high temperature ranging between -40°F and 68°F.

5W-20 is favorable for slightly warmer climates where temperature ranges between -31°F to 68°F.

3. Fuel Economy and Performance

0W-20 oil gives slightly better fuel efficiency than 5W-20 due to its lower viscosity and thinner oil flow.

Modern engines are designed with much tighter tolerances than older engines, allowing them to use low-viscosity 0W oil or 5W oil.

These low-viscosity oils prevent internal wear since they flow more easily, producing better fuel economy in newer engines. Further, they give you a better cold start. Low-viscosity oils also have a low flash point i.e., they can ignite faster.

4. Vehicle Owner’s Manual

To ensure you’re using the correct engine oil, consult your vehicle’s owner’s manual, which will specify the recommended viscosity grades.

If you own a newer vehicle compatible with both 0W oil and 5W oil, alternate between them based on the weather conditions.

5. Proper Certification

The oil brand you choose should have the logos of API (American Petroleum Institute) or ILSAC (International Lubricant Standardization and Approval Committee). These certifications indicate that the engine oils meet the minimum performance standards set by vehicle manufacturers.

Pennzoil Platinum, Phoenix, and Valvoline are some brands with these certifications.

6. Manufacturer Requirements

Heavy-duty vehicles or older engines should use high-viscosity oils that work well at a high temperature. These oils provide better engine wear protection.

On the other hand, lightweight vehicles with newer engines are more compatible with low-viscosity oils.

Most manufacturers use the ASTM D445 test to measure the kinematic viscosity of engine oils. The ASTM D445 test helps them determine the oil flow at particular temperature settings, ensuring effective lubrication.

Got more questions about these synthetic motor oils?
Keep reading.

4 FAQs about 0W-20 vs 5W-20 Oil

Here are answers to some common queries about 0W-20 vs 5W-20 oil:

1. Can You Use 0W-20 Instead of 5W-20?

Ideally, you shouldn’t switch to oil with a different viscosity than the one recommended by your car manufacturer.

0W20 oil is more suitable for passenger cars, light-duty vans, SUVs, and newer vehicle models with turbocharged engines. On the other hand, the 5W20 oil is apt for hybrid modern engines, gasoline engines, small-sized trucks, and multi-valve fuel-injected engines.

2. Can You Mix 0W-20 and 5W-20 Oil?

Ideally, you shouldn’t mix oils of different viscosity ratings. Mixing can alter the engine oil’s ability to maintain the appropriate viscosity across different temperatures, leading to ineffective lubrication.

Additionally, 0W-20 and 5W-20 oils contain different viscosity modifiers and corrosion inhibitors that may be incompatible with each other.

3. What Happens if You Put the Wrong Oil in Your Engine?

Adding an oil of unsuitable viscosity can damage your car’s critical engine parts, reducing its reliability and lifespan. Your car’s fuel efficiency will also take a hit. If you accidentally add the 20 weight oil instead of the recommended thinner oil to your car, drain it immediately and get an oil change.

Remember, using a thicker or thinner oil than the one recommended can also void your car’s warranty.

4. What’s the Oil Change Interval for 0W-20 or 5W-20?

The oil change interval for vehicles using 0W-20 and 5W-20 is generally similar. You should change the oil every 5,000 to 10,000 miles or every 6 to 12 months.

However, you should regularly check the oil level and top off as needed.

Keep Your Engines in Top Shape with the Right Oil

Both 0W-20 and 5W-20 oils are good choices for winter driving and colder climates due to their low pour point temperatures.

If you’re still unsure, check your owner’s manual for engine oil recommendations. Remember – regular oil changes are crucial to maintaining your car’s engine and preventing severe issues.

For expert advice, consult the seasoned mechanics at AutoNation Mobile Service.

We are a mobile auto repair and maintenance service available seven days a week. We provide upfront pricing, online booking facility, and a 12-month, 12,000-mile warranty on all repairs.