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Is it OK to use 5W 20 instead of 0W-20?

In most cases, you should not substitute 5W-20 for 0W-20 unless the vehicle’s manual explicitly allows it. Use the exact grade prescribed by the manufacturer to protect engine longevity, fuel economy, and warranty coverage.

Understanding what the oil numbers mean

The figures in a viscosity rating like 0W-20 or 5W-20 describe how an oil behaves at different temperatures. The first number with the W (0W or 5W) indicates cold-start flow. A lower number means the oil will flow more easily when the engine is cold. The second number (20) represents viscosity at engine operating temperature; both grades are designed for lightweight, fuel-efficiency engines and similar protection once the engine is warm. In practice, 0W-20 will flow more readily at very cold temperatures, aiding startup lubrication, while 5W-20 is slightly thicker during cold starts but still designed for cold-start reliability. At normal operating temperature, the two grades typically provide comparable protection, but their performance can differ in extreme conditions.

Because these details affect startup wear, fuel economy, and overall engine protection, manufacturers specify precise grades for each engine. Always cross-check the owner’s manual or official service bulletins before changing grades.

Is it OK to substitute 5W-20 for 0W-20?

There are situations where a substitute may be permitted, but only when the manufacturer explicitly allows it. Without official approval, using a different viscosity can affect lubrication performance, emissions, fuel economy, and warranty coverage.

The most important rule is to follow the manufacturer’s guidance. Some engines list 0W-20 and 5W-20 as acceptable options, while others require exactly one grade.

Climate and operating conditions matter. In very cold climates, 0W-20 is often recommended for easier cold starts; in milder environments, 5W-20 may be acceptable if approved.

Engine design and features can influence viscosity needs. Modern engines with turbochargers, direct injection, or variable oil pumps may require the thinner cold-viscosity of 0W-20 to ensure adequate oil pressure at startup.

Warranty implications should be considered. Using an oil not approved by the manufacturer can complicate warranty claims if lubrication-related damage occurs.

Bottom line: rely on the official specification. If the manual explicitly allows 5W-20 as an alternative, you can use it; otherwise, stick with the recommended grade and consult a dealer or technician if you’re unsure.

Practical steps if you’re unsure

If you don’t have the manual handy, contact the vehicle manufacturer or a qualified mechanic. Ask for the exact viscosity and spec (for example, 0W-20 with a particular API/ILSAC specification) recommended for your engine. When in doubt, err on the side of the OEM-approved oil to preserve performance and warranty coverage.

Summary

Oil viscosity matters for cold-start protection, fuel efficiency, and long-term engine health. While 5W-20 and 0W-20 share a similar hot-viscosity, their cold-start behavior differs, and substitutions should only be made when approved by the manufacturer. Always verify the exact grade and specification in the owner's manual or with a dealer. When in doubt, use the manufacturer’s recommended oil to ensure optimal performance and warranty protection.

What can I use instead of 0W-20 synthetic oil?

If SAE 0W-20 synthetic oil is not available, SAE 5W-20 conventional oil may be used.

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

Can I use 5w20 instead of 0W20 Silverado?

Yes, you can use 5W-20 instead of 0W-20 in a Silverado, but only if your vehicle's manual says it's acceptable, especially if you are in a hotter climate. While both oils behave the same at operating temperature, 0W-20 provides better cold-start protection and fuel economy, which is the primary reason it's recommended by manufacturers. Always check your owner's manual for the definitive answer, as using the wrong oil could affect your warranty.
0W-20 vs. 5W-20

Feature	0W-20	5W-20
Cold-start protection	Superior, especially in colder climates	Slightly less effective than 0W-20 in cold starts
Operating temperature	Identical viscosity to 5W-20	Identical viscosity to 0W-20
Fuel economy	Higher due to better cold-start performance	Slightly lower than 0W-20
Warranty	Often required for newer models	May void warranty if 0W-20 is specified
Availability	Typically full synthetic	Available as conventional or synthetic

Consult your owner's manual: The manufacturer's recommendation is the most important factor. If your manual specifies 0W-20, it's best to stick with it, particularly if your vehicle is under warranty.
Consider your climate: If you live in a consistently cold climate, 0W-20 is the better choice for engine protection during cold starts. If you are in a warmer climate, 5W-20 is more likely to be an acceptable substitute.
Check for GM's recommendations: General Motors recommends 0W-20 for many newer models for fuel economy reasons, so always check if your specific Silverado falls under this updated requirement.
Warranty impact: Using the wrong oil can affect your warranty coverage, so it's crucial to verify that 5W-20 is an approved substitute before switching.

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.

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.