Premium Vs Regular Gasoline: How Do They Differ?

Gasoline is a vital substance powering our cars daily. Have you ever stood at the pump, uncertain about choosing between regular or premium unleaded gas for your vehicle? You’re not alone. 

In this guide, we’re here to demystify the key differences between two major fuel options and help you make an ideal fuel choice. Let’s embark on this adventure together to explore the type of gas best for your car.

What Are The Key Differences Between Premium And Regular Gasoline?

The main difference between premium and regular gasoline is the octane rating, with regular gas having an 85 to 87-octane rating and premium gas having a higher rating at 91 to 94. This difference also explains the higher price of premium gasoline for its stability and lower risk of engine knock.

Gas prices at a pump

Octane Rating

  • Regular gas typically has an octane rating of 87, while premium gasoline offers a higher level, often between 91 and 94.
  • Octane rating measures a fuel’s resistance to premature ignition or knocking in your engine. Premium gasoline’s higher octane level helps prevent knocking more effectively than regular gasoline, leading to better engine performance.


  • Premium gasoline is generally more expensive than regular unleaded. For example, on 20/10/2023, regular type is priced at $3.558 for a gallon, while premium gas costs you $4.369 for the same amount (according to Gas Prices).
  • Using premium fuel can add up to significant costs over a year for frequent drivers. However, bulk purchases of premium gasoline may save money for certain fleets or heavy users, as it can help reduce wear and tear.

Engine Requirements

  • Turbocharged engines or those with a high compression ratio require high-octane fuel like premium gas to operate optimally.
  • Most vehicles today, especially modern ones, are designed to run efficiently on regular fuel. These newer engines are equipped with sensors and improved designs that reduce the likelihood of knocking, making it unnecessary to use premium gasoline for most everyday driving.

When To Use Premium And Regular Gas?

The choice between premium and regular gasoline hinges on various factors, such as your vehicle’s specific requirements and engine characteristics.

Premium Gas for High-Performance Engines

High-performance vehicles often feature unique engine characteristics, such as higher compression ratios or turbocharged systems, necessitating premium gasoline.

Using regular gasoline in a high-performance, premium-only vehicle can have detrimental consequences. It leads to reduced engine performance, decreased horsepower, and compromised fuel efficiency.

Prolonged use of regular gas in such engines can result in irreversible damage to the engine components.

Regular Gas for Most Vehicles

Enhanced Fuel Economy

The majority of vehicles on the road, especially those designed for everyday use, are optimized to run efficiently on regular gasoline.

If your owner’s manual does not specify the use of premium gas, your vehicle typically doesn’t require it.

Using regular gas in an engine that doesn’t demand premium fuel won’t cause harm, but you may not enjoy the full performance potential of your high-performance engine if it’s designed to use premium fuel.

The decision to use premium or regular gasoline should be based on your vehicle’s requirements, as outlined in the owner’s manual. 

Why Is It Beneficial To Use The Right Gasoline For Your Vehicle?

Using the wrong fuel type could reduce the engine’s performance, leading to knocking and potential long-term damage to the engine.

Using the correct fuel type ensures optimal engine performance, protects engine components, and supports efficient fuel injection, ultimately extending the life of your vehicle and preserving its performance capabilities.

Can I Mix Premium And Regular Gas?

mixing gas

Mixing premium and regular gas is generally safe, but it depends on your vehicle’s requirements and how consistently you do it. Modern engines are adaptable, but here’s the deal:

  1. Blend Formation: Gas stations mix fuels for midgrade gas. Your vehicle does a similar thing when you combine premium and regular gas.
  2. Modern Engines: Old cars couldn’t handle this mix, but modern engines are fine. It won’t harm your engine right away.
  3. Adaptability: If your car needs premium gas, but you can’t find it, using regular gas occasionally is okay. Long-term use of regular gas might impact performance.
  4. Engine Type Matters: Turbocharged or high-performance engines need higher-octane fuel. Consistent mixing can hurt their efficiency.
  5. Vehicle Compatibility: If your car runs on regular gas, a blend with premium won’t hurt. It could enhance mileage or performance. But if your car needs premium gas, consistent mixing can reduce efficiency.

Can You Use Regular In Premium-Only Cars?

Using regular gas in premium-only cars is not advisable. These high-performance vehicles are engineered to run optimally on premium fuel due to their high-compression engines and advanced technologies. 

Premium gasoline is formulated with specific additives and detergents tailored to high-performance engines, ensuring cleaner fuel injection and more efficient fuel economy.

While regular gasoline also contains EPA-mandated additives, premium gas, like Shell’s V-Power NiTRO+ and ExxonMobil’s Synergy Supreme+, offers additional protection against deposits, corrosion, wear, and friction.


Understanding the differences between regular and premium gasoline is crucial for informed choices. Regular gasoline is cost-effective and efficient for most cars, but high-performance vehicles requiring premium fuel should stick to it to maintain engine health.

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Alex Lewis

Alex Lewis

Petroleum Engineer At Rex Energy

I have worked in a variety of roles and professions, from quality engineering in the automotive industry to production engineer in the oil and gas sector. From a technical point of view, these roles have shown me how to design a process, ensure it is efficient and up to standard, and manage the execution of the said process from start to finish.

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