What kind of oil does my engine take?

In most modern engines, the exact oil depends on the vehicle's make, model, and engine. Many cars today use a synthetic oil in a specific viscosity (often 0W-20 or 5W-30), but you should verify the exact specification for your car.

How to determine the right oil for your engine

Use these steps to identify the precise oil specification for your vehicle. This helps ensure proper protection, performance, and warranty compliance.

1. Check the owner's manual or the manufacturer’s official website for the exact oil viscosity and specification (for example, SAE 0W-20 with API SP/ILSAC GF-6, or 5W-30 with a Dexos1 Gen 2 requirement). If you don’t have the manual handy, use the VIN to look up the correct specification through the manufacturer’s lookup tool.


2. Inspect the oil filler cap and the underside of the engine bay label, if present. Some caps indicate the required viscosity (such as 0W-20) or a recommended brand/spec.


3. Consult your dealer or a trusted mechanic. They can confirm the correct oil grade and specification for your exact engine variant.


4. Consider climate and driving conditions. Severe cold, hot environments, or heavy towing can influence the best viscosity for your engine within the manufacturer’s allowed range.


5. Avoid mixing oils with different viscosities or specifications. When in doubt, drain and replace with the recommended oil and a fresh filter.

By following these steps, you will confirm the correct oil viscosity and specification for your engine and help maintain performance and warranty coverage.

Understanding viscosity and specifications

Oil viscosity numbers (like 0W-20 or 5W-30) tell you how thick the oil is at different temperatures. The first number with the W indicates cold-start behavior; the lower the number, the better the oil flows when starting in cold weather. The second number describes the oil’s viscosity at operating temperature. In recent years, many engines require synthetic oils that meet specific standards such as ILSAC GF-6 or API SP, and some OEMs require brand- or model-specific certifications (for example, Dexos1 Gen 2 for certain GM vehicles, or VW 502.00/507.00 for some European models). Matching both viscosity and the OEM/spec standard is essential for performance and warranty protection.

Common oil types and viscosities you may encounter

Here is a practical guide to the types of oil you might see recommended for modern vehicles, along with where they tend to fit. This list helps you understand typical options, but always rely on your specific vehicle’s official guidance.

• 0W-20 synthetic: Very common in new and modern engines for fuel economy and strong cold-weather performance.


• 5W-30 synthetic: Widely used across many models and climates; suitable for a broad range of engines.


• 0W-16 or 0W-20: Used by certain high-efficiency engines (e.g., some Toyota/Lexus and Honda models) for improved efficiency.


• Conventional 5W-30 or 10W-30: Still specified for some older or budget vehicles; may be acceptable when synthetic isn’t required.


• Synthetic blends: Offer a balance between cost and performance; often used when full synthetic isn’t mandatory.

Concluding: The best choice depends on your engine design, climate, and maintenance plan. Always verify the exact viscosity and specification from the manual or dealer.

OEM-spec considerations you may see

Some vehicles require oils that meet specific OEM specifications beyond viscosity. Here are common examples and what they mean for oil selection.

• Dexos1 Gen 2: A GM specification that governs certain GM gasoline engines and requires compatible oils.


• VW 502.00/507.00, MB 229.5, BMW LL-01: Brand-specific European standards that indicate particular performance and protection criteria.


• ILSAC GF-6 and API SP: Industry-wide performance categories used for many gasoline engines worldwide.

Concluding: If your vehicle calls for an OEM-specific oil, use that exact specification rather than relying on viscosity alone.

What to do if you’re unsure

When you can’t locate the manual, use the VIN lookup tools on the manufacturer’s site or call the dealership. A quick note to your service advisor with your VIN will usually yield the exact oil grade and specification required for your engine.

Summary

Choosing the right engine oil involves confirming both the viscosity and the OEM specification for your vehicle. Start with the owner's manual or dealership lookup, then verify that the oil meets the specified standard (for example 0W-20 with GF-6 or Dexos1 Gen 2). Use only approved oils, avoid mixing different types, and follow recommended service intervals to protect engine life and maintain warranty rights. If in doubt, consult a professional to ensure you’re using the correct oil for your specific engine variant.

What happens if I use 5W-40 instead of 5w30?

Putting 5W-40 instead of 5W-30 will result in slightly decreased fuel efficiency and potential performance issues, but is unlikely to cause major damage, especially in warmer climates or for older engines. The main difference is that 5W-40 oil is thicker at operating temperature, which can slightly increase friction and oil pressure. It's always best to follow the manufacturer's recommendation, which is found in your owner's manual or on the oil fill cap. 
What to expect

• Slightly reduced fuel economy: Thicker oil creates more drag on engine components, leading to a small decrease in fuel efficiency. 
• Potential performance impact: A thicker oil may slightly reduce high-end horsepower. 
• Increased oil pressure: 5W-40 has higher viscosity, which can lead to higher oil pressure readings. 
• Potential benefit for older engines: A thicker oil may be beneficial for older, high-mileage engines that have increased wear and tear, as it can help maintain oil pressure. 
• No harm in cold starts: The "5W" rating is the same for both oils, meaning both will have similar flow characteristics during cold starts. 

When to be cautious

• Modern engines: Modern engines are designed with precise tolerances, and using a thicker oil can cause problems that the manufacturer did not design for, so it is best to stick with the recommended 5W-30. 
• Warranty issues: Using an oil that does not meet the manufacturer's specifications can potentially void your warranty. 
• Stop-and-go traffic: If your engine runs hot in stop-and-go traffic, the thicker oil could be a benefit. 

Best practices

• Check your owner's manual: The manufacturer's recommendation is the safest guide. Check the manual for the correct oil viscosity and specifications. 
• Don't switch for "just because": There's no need to switch from 5W-30 to 5W-40 unless you have a specific reason, such as a high-mileage engine or a preference for heavier oil in a hot climate. 
• Stick to a single type: If you do switch, make sure to use the new oil at your next oil change, as mixing different viscosities is not ideal. 

How do I know what oil my engine takes?

To check your engine oil type, consult your car's owner's manual, look for the required oil specification on the oil filler cap or dipstick, or use an online oil finder tool. The correct oil is specified by its viscosity grade (e.g., 5W-30) and any other manufacturer specifications listed in your manual. 
Methods to check engine oil type

• Consult the owner's manual: This is the most reliable source for the exact oil viscosity and specifications your car requires, including whether it needs conventional, synthetic, or a blend. 
• Check the oil filler cap or dipstick: The correct viscosity grade is often printed directly on the oil filler cap or sometimes on the dipstick itself. 
• Use an online oil finder tool: Many oil manufacturers and auto parts retailers have online tools where you can enter your vehicle's make, model, and year to find the recommended oil type. 
• Examine the current oil bottle: If you have the old oil bottle, the product name, viscosity, and specifications will be on the back, as noted by this YouTube video. 

What the numbers mean (e.g., 5W-30)

• The first number and 'W' (e.g., 5W): This indicates the oil's viscosity at cold temperatures. A lower number means the oil flows better in cold weather, which is important for starting the engine on cold days. 
• The second number (e.g., 30): This indicates the oil's viscosity at normal operating temperature. 
• High-mileage engines: If your car has over 75,000 miles, a high-mileage oil might be a good option, as it is formulated to help with wear and tear. 

Will the wrong oil damage my engine?

Yes, the wrong oil can damage your engine over time by causing increased friction, overheating, and wear on critical components. While it may not cause immediate destruction, using an incorrect oil viscosity or type can lead to gradual damage, reduced fuel efficiency, and other issues. The longer the wrong oil is used, the greater the risk of damage, so it is important to drain the incorrect oil and replace it with the manufacturer's recommended type as soon as possible. 
How the wrong oil can damage your engine

• Increased friction and wear: An oil that is too thick or too thin may not properly cushion moving parts like pistons, bearings, and camshafts, leading to premature wear. 
• Overheating: Improper lubrication from the wrong oil can lead to excessive heat buildup, which can damage sensitive components and cause the engine to overheat. 
• Reduced fuel efficiency: Increased friction from the wrong oil can make the engine work harder, leading to decreased fuel economy. 
• Oil flow and pressure issues:
  • Too thick: Thick oil can have trouble circulating quickly, especially on cold starts, leading to a lack of lubrication in the upper parts of the engine and a potential clicking or knocking sound. 
  • Too thin: Thin oil may not maintain adequate pressure at high temperatures, which can cause the oil pressure light to flicker. 
• Component malfunction: The wrong oil can affect the performance of hydraulic systems, like variable valve timing solenoids, making the engine sluggish. 

What to do if you used the wrong oil

• Drain and replace: The best course of action is to drain the incorrect oil and replace it with the proper type specified in your owner's manual. 
• Change the filter: When you replace the oil, also change the oil filter. 
• Don't wait: Do not wait for your next scheduled oil change to fix the problem. The longer the wrong oil circulates, the more damage it can cause. 

What happens if I put 5W-30 instead of 5W-20?

Putting 5W-30 in an engine that calls for 5W-20 is generally not a major issue for short-term use, but it can lead to slightly reduced fuel efficiency and may affect variable valve timing systems. Over time, the thicker oil may cause slightly more wear, so it's best to switch back to the recommended 5W-20 at your next oil change. 
Effects of using 5W-30 instead of 5W-20

• Slightly lower fuel economy: 5W-30 is thicker at operating temperature, so the engine has to work slightly harder to pump it, which can lead to a small reduction in gas mileage. 
• Impact on variable systems: Modern engines with variable valve timing (VVT) or similar systems rely on specific oil viscosity for proper function. A thicker oil can alter the system's pressure and performance, though this is often a minor effect. 
• Increased engine pressure: The increased thickness can lead to a slightly higher pressure inside the engine. 
• Potential for minor wear: While the extra wear is very slight and unlikely to cause immediate damage, it's a consideration for long-term use, as the engine was designed for the thinner 5W-20 oil. 

What to do

• Don't panic: Driving with 5W-30 for a short period will not cause immediate, significant damage to most engines. 
• Change to the correct oil: At your next opportunity, get an oil change and replace the 5W-30 with the manufacturer's recommended 5W-20 oil. 
• Monitor your engine: Listen for any unusual noises and check for any changes in performance as you continue to drive. 
• Check the owner's manual: Always refer to your vehicle's owner's manual for the specific oil viscosity recommended for your engine, as it's the most reliable source of information.