What happens if I put regular fuel instead of premium?

If you accidentally fill your vehicle's tank with regular gasoline instead of the recommended premium fuel, it's generally not a major issue. However, it's important to understand the potential consequences and take the appropriate steps to address the situation.

Understanding the Fuel Recommendation

Automakers typically recommend the use of premium fuel (higher octane rating) for certain vehicles, usually high-performance or luxury models. This is because these engines are designed to operate more efficiently and with higher compression ratios, which require the higher octane fuel to prevent knocking or pinging during combustion.

Potential Consequences of Using Regular Fuel

Using regular fuel in a vehicle that requires premium can have the following consequences:

• Reduced performance: The engine may experience a noticeable decrease in power, acceleration, and overall performance. This is because the lower octane fuel is more prone to premature ignition, which can cause knocking and reduce the engine's efficiency.


• Increased fuel consumption: The engine may need to work harder to compensate for the lower octane fuel, leading to increased fuel consumption and reduced fuel economy.


• Long-term engine damage: Prolonged use of regular fuel in a premium-recommended engine can potentially cause more serious issues, such as increased wear on engine components, carbon buildup, and even damage to the catalytic converter.

It's important to note that the severity of these consequences can vary depending on the specific engine design, driving conditions, and the frequency of using regular fuel in a premium-recommended vehicle.

What to Do If You Accidentally Use Regular Fuel

If you realize you've filled your tank with regular fuel instead of premium, here's what you should do:

• Do not start the engine: If possible, avoid starting the engine until you've addressed the issue.


• Drain the fuel tank: The best solution is to have the fuel tank drained and refilled with the recommended premium fuel. This will ensure that the engine is not subjected to the lower octane fuel.


• Consider a fuel system cleaner: After refilling with premium fuel, you may want to consider using a fuel system cleaner to help remove any residual regular fuel and prevent potential long-term issues.


• Monitor the engine's performance: Pay attention to any changes in the engine's performance, fuel efficiency, or unusual noises after refueling with the correct fuel. If you notice any issues, it's best to have your vehicle inspected by a qualified mechanic.

In summary, while using regular fuel in a premium-recommended engine is generally not a catastrophic issue, it's important to address the situation promptly to avoid potential long-term consequences and maintain your vehicle's optimal performance.

What happens if you put regular instead of premium?

If you put lower-octane fuel into your high-octane vehicle, whether by mistake or to save money on gas, you'll probably notice the effects right away: things like poor fuel economy, reduced acceleration, and spark knock, which sounds like a high-pitched pinging or rattling noise.

Is it bad if I mix 87 and 93 gas?

No, it is not bad to mix 87 and 93 octane gas; the result is a fuel with an octane level between the two, and most modern cars can adapt to a mixed fuel without damage. However, mixing gas grades offers no performance benefits and may lead to reduced performance, especially if your car requires premium (93 octane) gas for optimal operation. 
What to consider

• Engine adaptability: Modern cars have engine control modules (ECMs) that can adjust engine timing to compensate for lower-octane fuel, preventing knocking or pinging. 
• Performance impact: Your car may experience a slight decrease in power and fuel efficiency, though the difference is often unnoticeable. 
• Car manufacturer recommendations: It's always best to follow the octane rating specified in your owner's manual. If your car recommends 93 octane, using 87 or a mix of the two long-term is not ideal and could impact performance. 
• Safety for specific engines: If you have a high-performance or turbocharged engine, it's especially important to use the manufacturer's recommended octane level to avoid damage. 
• How it works: Mixing the two grades simply creates a new fuel with an octane level that is an average of the two, weighted by the volume of each fuel. For example, a 50/50 mix of 87 and 93 will result in approximately 90 octane. 
• A practical example: Many stations already blend 87 and 93 octane to create midgrade (89 octane) fuel, so mixing them is a similar process. 

What happens if I put 93 instead of 95?

If a car requires 95 octane and you use 93 octane, the main risk is engine knock or pinging, which can damage the engine over time, especially in turbocharged or high-compression engines. Modern cars have knock sensors that can adjust engine timing to prevent this damage, but this will reduce performance, acceleration, and possibly fuel economy. It is always best to consult your owner's manual to determine your car's specific requirements. 
Potential consequences of using 93 instead of 95 octane

• Engine knock or pinging: The fuel can detonate prematurely, causing a rattling noise, particularly during acceleration. 
• Reduced performance: The engine's computer will likely retard the engine timing to prevent damage, resulting in less power and acceleration. 
• Lower fuel efficiency: You may notice a decrease in gas mileage. 
• Engine damage: If the knocking is severe or persistent, it can cause internal engine damage. 
• Voided warranty: Using fuel with a lower octane than required can potentially void your vehicle's warranty. 

What to do if you accidentally use 93 instead of 95

• Avoid hard acceleration: Drive gently to minimize the risk of knocking. 
• Fill up with premium fuel next time: When you need to refuel, use 95 octane to bring the fuel mixture back to the correct level. 
• Check your owner's manual: Always consult your car's manual to understand its specific fuel requirements. 

What happens if you put 87 gas in a 91 car?

If you put 87 octane instead of 91 octane in a car that requires 91, you will likely experience a decrease in performance and fuel efficiency, but it won't cause permanent damage in a single instance. Modern cars can adjust their engine's timing to compensate for the lower octane fuel by reducing power and may trigger a "check engine" light if the issue persists. 
How the car's computer responds

• Modern engines are designed to detect "knocking" or "pinging," which occurs when fuel combusts unevenly under high compression. 
• When the car's engine control unit (ECU) senses this, it will automatically adjust the ignition timing to prevent damage. 
• This adjustment results in less power and a potential reduction in fuel economy. 

What you might notice

• Slightly slower acceleration.
• A decrease in fuel efficiency.
• You may not notice any difference at all, depending on the car and your driving habits. 

What to do

• Just drive the car normally until the tank is nearly empty. 
• Fill up with the recommended 91 octane fuel on your next visit to the gas station. 
• Avoid driving aggressively or pushing the engine, especially during hard acceleration. 
• Do not make this a regular habit, as extended use could lead to engine damage.