Can You Mix Regular And Premium Gas?

It’s a common question car owners ask – can you combine higher octane gasoline with regular gas in your car?

The article below will explore the differences between regular gas and premium gas and whether these two gas types can be mixed in your car engine.

Is It Okay To Mix Regular And Premium Gas?

The answer is yes and no. When you mix regular and premium gas, it may alter the performance of your vehicle. Cars that only run on premium fuel will have a reduced performance when that fuel is combined with a lower octane fuel. Other cars that use regular fuel may not cope well with higher octane gasoline.

Mixing regular and premium gas is not recommended; however, it is expected to have a minimal impact on your car’s performance. Cars that require premium fuel that are filled with regular fuel may see a decrease in performance and experience what is called “engine knock.”

There are also other factors to consider, which we will look at in more detail in the article below.

What Happens If You Mix Regular And Premium Gas?

Modern vehicles have advanced technology in their engines. Car engines that were manufactured within the last decade are able to detect which type of fuel has been used.

Older vehicles may develop an engine knock sound. This is because these older models have fixed fuel injectors and a fixed ignition time. Modern cars are able to adjust their parameters in accordance with the type of fuel that is used.

Mixing premium gas with regular unleaded gas will impact the octane levels and may influence your gas mileage in the long run, especially if your car requires premium fuel. If you were in a situation and had to mix fuel types, it is best to top up with your required fuel type when possible.

What Is Premium Gas?

Premium gasoline is a type of higher octane fuel. It is frequently used in high-performance vehicles. The octane level refers to how much compression the gasoline can withstand before igniting.

High-performance cars tend to have powerful engines. With higher compression ratios in these engines, they require a higher octane gas to work properly. This does not mean that regular gas will impact performance, though.

Octane rating: 91 and above

What Cars Require Premium Gas?

Below is a list of some cars that require a higher octane rating fuel in 2022.

  • Jeep Renegade
  • Mitsubishi Outlander
  • Nissan Juke
  • Buick Regal
  • Buick Envision
  • Subaru Forrester
  • Chevrolet Malibu
  • Mini COOPER.

What Is Regular Gas?

Regular gas, also called unleaded gas, is the most commonly used type of fuel in cars. “Regular” used to refer to leaded gasoline. However, lead has been banned from gasoline in most countries; therefore, regular gas refers mostly to unleaded gas with a lower octane level.

Octane rating: 87 (regular gas); 89 – 90 (Mid-grade gas)

What Cars Use Regular Gas?

Below is a list of luxury cars that use regular gas. It is the most commonly used gas.

  • Hyundai Equus
  • Lexus ES350
  • Cadillac ATS
  • Buick LaCrosse
  • Volvo S60
  • Lincoln MKX.

Most cars use regular gas, and the list would be incredibly long if we were to list every car that depended on regular unleaded gas.

How Do You Tell Which Type Of Fuel Your Car Uses?

You should consult your car manual if you are uncertain whether your car takes premium fuel or regular gas. If you have misplaced the manual, there should be a sticker inside the fuel door (the flap you open to get to the fuel cap and fuel tank). This sticker should indicate whether your car takes diesel or petrol, and also the octane rating required in the case of petrol.

Will Mixing Premium And Regular Gas Mess Up Your Car?

If a lower octane gas is mixed with a small amount of higher octane gas, then the octane level will remain low. If you were to mix a large volume of gas with a higher octane rating with gas with a lower octane rating, then the resulting octane level would be high.

So, is it okay to mix these gas types?

If your car requires a low octane gas, then mixing premium fuel with regular fuel will not do a lot of harm. However, it will also not offer any advantages, despite people believing that putting premium fuel in a regular gas car will offer better performance.

If you fill a car that requires premium gasoline with regular gas, ignition will not happen at the right time, and there is a small chance your vehicle will be damaged. However, modern engines are able to detect the octane ratings and can adjust performance and ignition accordingly.

Can You Switch From Regular To Premium Gas And Vice Versa?

It is not recommended that you switch between gas types.

Older cars that require higher octane fuels may instantly experience “knocking” when filled with lower octane gas. As mentioned already, more modern engines that require premium gas should be able to detect the octane fuel levels and adjust accordingly. So it will come down to the age of your premium gas car.

Cars that require regular gas are also unlikely to benefit from the use of premium gas. However, if you are in a pinch and it is the only fuel type available, you can fill up with high octane fuel.


Does premium gas last longer?

Premium gas is only defined by the octane level, which determines the combustion in the engine. Premium fuel, therefore, does not last longer or make your car drive further.

There are things you can do to make your gas last longer, such as using a car with an excellent fuel economy, removing excess weight from the car, and giving your car regular maintenance.

Is unleaded gas regular gas?

Yes. Regular gas is also called unleaded gasoline. There is a worldwide ban on lead in gasoline by the United Nations, so therefore all regular gas is “unleaded.”

Is super unleaded the same as premium?

Yes. Premium fuel is often called “super” or “high performance” unleaded gasoline.

Is it bad to mix gas from different stations?

Different gas stations may use various additives in the fuel. However, there is no problem with mixing gas from different stations.

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Author: DJ

Dave Junior is a hands-on automotive technician with experience in performing service, diagnostics, and repairs on domestic and imported vehicles. He enjoys writing and sharing his knowledge far and wide.

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