Home FAQ

Can 0W20 be used instead of 5w20?

Yes, but only if your vehicle’s manufacturer explicitly allows it. If the manual specifies 5W-20 (or a narrow viscosity window that excludes 0W-20), you should not substitute. When the manual lists a range that includes 0W-20, or explicitly permits it, switching is typically acceptable and can offer cold-start and fuel-economy benefits.

Understanding whether you can swap 0W-20 for 5W-20 hinges on engine design, warranty requirements, and the oil specifications the manufacturer endorses. The two oils differ mainly in their cold-temperature behavior, while their performance at operating temperature is often similar. This article explains what those differences mean for your engine, how to check compatibility, and the steps to switch safely if permitted.

Understanding viscosity labels and manufacturer specs

Viscosity grades tell you how an oil flows at different temperatures. The first number with a W (winter) indicates cold-start flow—the smaller the number, the quicker the oil will reach engine parts when the engine is cold. The second number (20 in both cases) describes the oil’s high-temperature viscosity when the engine is hot. In practical terms, 0W-20 is thinner at cold temperatures, but both 0W-20 and 5W-20 typically offer similar protection once the engine reaches operating temperature. The key is whether the engine’s design and the manufacturer’s specifications permit the change.

Before considering substitution, consider these factors that determine whether it's acceptable:

Owner's manual and oil specification: If it explicitly requires 5W-20 or lists a narrow viscosity window, follow that; if it states 0W-20 is acceptable, you may switch.

Climate and operating temperature: 0W-20 helps cold starts and may be preferred in cold climates; in hotter climates, ensure the oil still falls within the approved range for your engine.

Engine design and tolerances: Some engines with tight tolerances or turbocharging rely on a specific viscosity for lubrication and oil pressure regulation.

Warranty and service requirements: Using an oil outside the approved specification can affect warranty coverage if lubrication-related failures occur.

Oil specifications and approvals: Ensure the oil meets API/ILSAC (and any OEM) requirements demanded by your engine (for example Dexos, VW 502.00, BMW LL, etc.).

Consistency with high-temperature viscosity and protection: Both 0W-20 and 5W-20 are commonly approved for many engines, but always confirm the exact grade is allowed for your model.

Bottom line: If your manual calls for 5W-20 and does not allow 0W-20, do not substitute. If it lists both grades or permits a range that includes 0W-20, switching is generally acceptable and can offer benefits in cold weather; always verify with the OEM recommendation.

If the manual allows 0W-20, how to switch safely

If the owner’s manual permits 0W-20, follow these steps to switch safely and maintain engine protection:

Verify the oil specification: Ensure the 0W-20 you plan to use meets the exact API/ILSAC rating and any OEM approvals required by your engine (for example, Dexos or other brand-specific specs).

Plan a proper oil-change procedure: Do a full oil change—drain the old oil and replace the oil filter—with the new 0W-20 that meets the spec. Avoid mixing different oil grades to maintain predictable performance.

Match the fill to the specification: Use the correct 0W-20 grade that is approved for your engine; avoid using a 0W-20 that lacks the required approvals or that falls outside the specified viscosity window.

Consider top-ups and monitoring: If you need to top up between changes, ensure the supplemental oil still meets the same spec; mixing different viscosities is discouraged unless explicitly allowed by the manufacturer.

Run and verify: After the change, drive normally and monitor for any unusual noises, oil pressure readings, or warning lights. Check for leaks and recheck oil level when the engine is warm.

Follow the recommended oil-change interval: Adhere to the OEM-recommended interval for your vehicle with the chosen oil grade; some engines may tolerate longer or shorter intervals depending on oil quality and driving conditions.

Bottom line: With manual approval, a switch to 0W-20 is typically straightforward, but always confirm approvals and follow proper oil-change procedures to preserve engine health and warranty coverage.

Additional notes on performance and warranties

In practice, 0W-20 is widely used in modern gasoline engines to improve cold-start lubrication and fuel economy. The actual fuel-saving benefits are modest and vary by vehicle, driving conditions, and climate. The most important consideration is staying within the OEM’s approved viscosity and specification. If you switch without approval, you risk reduced lubrication efficiency in certain operating ranges and possible warranty implications.

Summary

The short answer is: you can use 0W-20 instead of 5W-20 only when the vehicle manufacturer explicitly allows it. Always consult the owner’s manual and verify that the oil meets the required specifications and approvals. If permitted, switching can offer better cold-start performance and potential fuel economy benefits, provided you follow correct oil-change procedures and monitor engine health after the change. When in doubt, contact a dealership or qualified mechanic to confirm compatibility for your exact engine and model.

Will 5W-30 damage my engine if 0W-20 is specified?

Modern engines designed for 0W-20 oil require specific viscosity for optimal performance, and using thicker 5W-30 oil may compromise efficiency while potentially voiding manufacturer warranties.

Is 5W20 better than 0W20 in hot weather?

For hot weather, 5W-20 is generally a safer bet than 0W-20, especially for engines with higher mileage or those that experience sustained high-heat conditions. While both oils have the same viscosity at operating temperature, 5W-20 has slightly higher viscosity when cold, which can be beneficial in high-mileage engines. In extreme heat, 0W-20 can lose more film strength, leading to increased wear, while 5W-20 may offer better protection due to its slightly higher viscosity in a hot climate.
0W-20 vs. 5W-20 in hot weather

Feature	0W-20	5W-20
Hot Weather Performance	Can lose more film strength in extreme heat, potentially leading to increased wear.	Offers better protection in high-heat conditions due to slightly higher viscosity.
High-Mileage Engines	Not ideal, especially with expanded bearing clearances. The higher viscosity of 5W-20 is better for oil pressure maintenance.	Benefits from slightly higher viscosity for better oil pressure maintenance.
Cold Weather Performance	Flows more easily at very low temperatures, providing better cold-start lubrication.	Flows slightly slower than 0W-20 at very low temperatures.
General Recommendation	Best for cold climates where the primary concern is cold-start protection.	Suitable for warm climates and year-round use, especially in high-mileage engines.

For a modern engine in a hot climate: Either is likely fine, but 5W-20 is a slightly safer choice if you frequently encounter high heat or have concerns about long-term engine health, say users on Reddit.
For an older or high-mileage engine: It is best to use 5W-20 to ensure proper oil pressure and reduce wear, according to heavyvehicleinspection.com.
For extreme temperatures: If you drive in both extreme cold and extreme heat, consider using a heavier weight oil like 5W-30 (if the manufacturer recommends it) for added protection during the hottest months, say users on Reddit and YouTube.
Always check your owner's manual: The manufacturer's recommendation is the most important factor in choosing the right oil for your engine, say users on Reddit and Quora.

What can I use instead of 5W20?

You can use 0W-20 oil as a substitute for 5W-20, as both are the same viscosity at operating temperature and the 0W-20 flows better when cold. However, it is best to check your owner's manual first to confirm any specific requirements and whether other options are acceptable for your vehicle, especially for modern engines or if your vehicle is under warranty.
Acceptable substitutes

0W-20: This is the most common and often recommended alternative because it is the same thickness as 5W-20 once the engine is warm, but it is thinner when cold, which can help with cold starts.
5W-30: In some cases, your manufacturer may state that 5W-30 is an acceptable alternative, but it is thicker than 5W-20 when warm. This can lead to slightly reduced fuel efficiency and may put extra strain on older engines, so always check your owner's manual.

Factors to consider

Owner's manual: Always consult your owner's manual first. The manufacturer's recommendation is the most important factor for your specific engine's needs and your warranty status.
Engine design: Modern engines are often designed with tighter tolerances, which is why they are specified for 5W-20 or 0W-20. Using a thicker oil like 5W-30 in these engines can cause increased resistance.
Climate: While 5W-20 is a standard for many climates, 0W-20 is often preferred in very cold weather due to its superior cold-flow properties.
Vehicle age/mileage: On high-mileage vehicles, a slightly thicker oil might be used, but this should be a recommendation from a mechanic who has inspected the engine.

Can 5W20 and 0W20 be mixed?

Yes, you can mix 0W-20 and 5W-20 motor oils, especially for topping off, as they are highly compatible, with the primary difference being the "0W" and "5W" cold-flow viscosity ratings. Mixing them is generally safe, but it is best to consult your owner's manual to confirm that 5W-20 is an acceptable alternative and to switch to a single type at your next oil change if you are not in an emergency situation.
You can watch this video to learn how mixing 0w20 and 5w20 can affect your engine's performance: 57sMotor MatchupsYouTube · Jul 27, 2024
Considerations for mixing oil

Compatibility: 0W-20 and 5W-20 are compatible. Both have a viscosity of 20 at operating temperature. The "W" (winter) rating is simply a measure of cold-temperature performance, and 0W-20 flows more easily than 5W-20 in very cold conditions.
Emergency use: Mixing is most common and acceptable in an emergency when you need to top off the oil and do not have the correct type available.
Long-term use: While mixing is acceptable for top-offs, it is a good idea to use a single, recommended oil type for all your oil changes to ensure peak performance and longevity, especially if your engine has features like variable valve timing that are sensitive to oil viscosity.
Engine wear and performance: Mixing viscosities is less likely to cause problems than running low on oil, but a small risk of engine wear exists if you use the wrong oil for an extended period. For long-term use, stick to the manufacturer's recommendation in your owner's manual.
Oil type: Always try to mix the same type of oil (e.g., conventional with conventional, or synthetic with synthetic).

This video explains the importance of using the correct type of motor oil: 45sRevZillaYouTube · Aug 19, 2023

Kevin Bennett

Company Owner

Kevin Bennet is the founder and owner of Kevin's Autos, a leading automotive service provider in Australia. With a deep commitment to customer satisfaction and years of industry expertise, Kevin uses his blog to answer the most common questions posed by his customers. From maintenance tips to troubleshooting advice, Kevin's articles are designed to empower drivers with the knowledge they need to keep their vehicles running smoothly and safely.