What happens if I put 5w30 instead of 5w20?

Using the wrong engine oil viscosity in your car can have significant consequences. If you put 5W30 oil instead of the recommended 5W20, it may not provide adequate lubrication and protection for your engine, leading to potential damage over time.

Understanding Engine Oil Viscosity

Engine oil viscosity is a measure of the oil's resistance to flow, and it's denoted by a number-letter combination, such as 5W20 or 5W30. The first number (5 in this case) indicates the oil's viscosity at low temperatures, while the second number (20 or 30) represents the oil's viscosity at high temperatures.

The "W" stands for "winter," and it refers to the oil's ability to flow easily during cold weather starts. A lower number, such as 5W, indicates the oil will flow more easily in colder temperatures compared to a higher number like 10W.

Potential Issues with Using 5W30 Instead of 5W20

• Reduced Fuel Efficiency: 5W20 oil is designed to be thinner and flow more easily, which can improve fuel efficiency. Using a thicker 5W30 oil may result in increased engine drag, leading to reduced fuel economy.


• Decreased Engine Protection: 5W20 oil is engineered to provide optimal lubrication and protection for the engine's moving parts, especially during cold starts. Using a thicker 5W30 oil may not provide the same level of protection, potentially leading to increased wear and tear on the engine over time.


• Reduced Engine Performance: The thicker 5W30 oil may not flow as easily through the engine's narrow passages and oil galleries, potentially reducing the engine's overall performance and responsiveness.


• Potential Damage: In some cases, using the wrong oil viscosity can cause significant damage to the engine, such as increased friction, higher operating temperatures, and even premature engine failure.

It's important to always follow the manufacturer's recommended oil viscosity for your specific vehicle, as this ensures the engine receives the proper lubrication and protection it needs to function optimally.

What happens if you put 5W30 in a 5W20 engine?

Using 5W-30 instead can reduce fuel economy and impede flow throughout the engine. While using it temporarily in a pinch likely won't cause your engine lasting harm, remember that the engineers who built your engine did so with a specific viscosity oil in mind, meaning it's best to stick with it.

What happens if you put a little bit of the wrong oil in your car?

Use only what the owner's manual specifies. Using the wrong oil can lead to reduced lubrication and shorter engine life. If the manual says to use synthetic oil, do so. Contrary to what some believe, adding synthetic oil to regular oil won't harm the engine, but there's also no benefit in doing so.

Can I use 5W30 instead of 5W20 in my Honda?

Yes, you can use 5W-30 instead of 5W-20 in your Honda, as some Honda manuals allow it. While 5W-20 is recommended for better fuel economy, 5W-30 offers slightly better protection under higher temperatures or heavy-duty use, though it may slightly decrease fuel efficiency. 
Which oil to choose

• For fuel economy: Use 5W-20, as it is thinner and reduces friction. 
• For heavy-duty use or higher temperatures: Consider using 5W-30, as it provides more protection in demanding conditions. 
• Check your owner's manual: Always consult your owner's manual for the most accurate information on the correct oil viscosity for your specific vehicle model and year. 

How the oils differ

• Cold temperature performance: The "5W" in both oils indicates viscosity in cold weather. Both oils have the same cold-weather performance. 
• Hot temperature performance: The second number (20 or 30) indicates viscosity at operating temperature. 5W-30 is thicker than 5W-20 when hot, offering more protection but creating more drag. 

Potential consequences

• Fuel economy: Using 5W-30 may result in a slight decrease in fuel economy compared to 5W-20. 
• Engine performance: In most daily driving situations, the difference is minimal and won't cause any issues. However, modern engines with tight tolerances may be optimized for 5W-20, and using a thicker oil could potentially cause flow issues in some cases, though this is unlikely with a minor viscosity jump like this. 

Can I use 5W30 instead of 5W20 in my Hyundai Sonata?

Yes, you can likely use 5W-30 instead of 5W-20 in your Hyundai Sonata, as many models tolerate both viscosities. While 5W-20 is often recommended for fuel efficiency, 5W-30 is a suitable alternative and can sometimes lead to a smoother, quieter engine, especially in warmer climates or for engines with more miles on them. However, always check your owner's manual for the most precise recommendation for your specific model year and engine. 
When to use 5W-30

• Warmer climates: 5W-30 is a good option for hot climates, as it can offer better protection in high temperatures. 
• Older engines: If your car has high mileage, the slightly thicker 5W-30 oil can provide better lubrication and help quiet down the engine. 
• For potentially better performance: Some drivers report smoother operation and quieter engine sounds after switching to 5W-30, though this can vary by engine. 

Important considerations

• Check your owner's manual: Always consult your owner's manual for the most accurate information for your specific vehicle. 
• Fuel economy: 5W-20 is generally recommended for optimal fuel economy due to its thinner viscosity, but 5W-30 will not significantly harm your fuel efficiency. 
• Engine protection: The oil pump will adjust to the thicker oil, ensuring it still circulates to all engine components. It's the thickness at operating temperature that matters, not just the cold viscosity rating. 
• Certification: Whichever oil you choose, make sure it meets the required American Petroleum Institute (API) or International Lubricant Standardization and Approval Committee (ILSAC) certification standards for your engine.