Understanding Gas-Powered Cars And Their Fuel Options


A look at the different types of gasoline and how each affects car performance

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Not every gasoline engine is the same, with some focusing more on performance than others; this, in turn, requires a type of gas conducive to higher outputs. But, understanding how gasoline cars work also means we need to know the exact meaning of terms like premium, midgrade, and octane, when it comes to fuelling these cars. This guide is designed to make the great regular vs premium gasoline debate a little more understandable.

Gasoline Pexels.com

How Do Gasoline Engines Work?

The fundamental principle of an internal combustion engine (ICE) is that a mixture of fuel and oxygen is ignited to create thousands of small explosions within the engine, with the resultant force being used to turn a crankshaft. This, in turn, activates the pistons to turn the wheels. The type of gasoline used is important, in that certain grades of gasoline have a higher octane level than others, with octane referring to how likely combustion is to occur at the wrong time.

So, What is Octane?

Simply put, this pertains to the ability of the gasoline to resist igniting at the wrong time, which is also referred to as 'knock' or 'auto-ignition'. Higher octane fuels can withstand increased compression and resist knock better than lower grades - this also then answers the question, what is premium gas? The main grades or types of gasoline for cars sold in the USA include:

  • Regular - 87 octane
  • Midgrade - 89 octane
  • Premium - 91 - 93 octane
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Different Types Of Gasoline unsplash.com

Premium Gas vs Regular Gas

While there are many different types of fuel used in the USA (which we elaborate on more here), gasoline remains the most commonly used, and when weighing up the pros and cons of premium vs regular gas, and which gas is better, the following is important to note:

  • Know what is recommended for usage in your car's tank - and stick with it
  • Using premium fuel when regular will do does not clean the engine, improve performance, or yield lower fuel consumption figures, and doing so just because it's at your disposal is an unnecessary expense
  • Premium gas should always be used when stipulated in high-performance engines - using regular when premium is required could lead to engine knock, reduced performance, and inefficiency
  • If premium gas is a recommendation and not a requirement, the choice is yours, and either fuel type will do - expect only slight performance and efficiency increases, however, when using premium
Gas Octane Levels freepik.com

Comparing Gasoline Prices

Gasoline prices are directly proportional to their octane ratings, meaning you can expect a higher price from higher octane fuels. In terms of the premium vs regular gas price, premium will thus always be more expensive.


It is important to be aware of the grade of fuel your vehicle requires when you go to fill up. The majority of gas stations in the US offer a variety of fuel types for sale, and, while you may be tempted to add premium gas to your daily runabout, you should only do so when this will actually benefit performance. Every type of car, from a family sedan like a Honda Accord or a compact SUV like a Nissan Rogue, to a hybrid vehicle like a Toyota Prius, will have a different fuel requirement. Always use what the manual dictates to be sure that you get optimal performance and miles per gallon from your engine.


What happens when I use regular gas instead of premium gas?

If your car is designed to run on premium fuel and you put regular gas in, most modern engines will protect themselves by reducing power. It won't run optimally, so you should top off with premium at the first opportunity. Older engines requiring premium may suffer 'knock' and subsequent damage when regular gas is used for a prolonged period of several weeks or months.

How do I know what type of gas I am supposed to pump into my car’s tank?

It is generally stated in your owner's manual and usually indicted on a sticker of sorts, located on the inside of your fuel cap flap. You should not use a different gas than is stipulated.

How many gasoline cars are in the US?

In 2019, an estimated 276 million cars and trucks were registered in the US, with the vast majority being gas cars. Only about 1.8% of all new cars sold in 2020 were EVs, but this is 20% more than the 1.4% in 2019. A contributing factor to this could be the tax incentives offered by most governments. However, currently, the gasoline vehicle still dominates the market.

What is Ethanol fuel?

Ethanol is a combustible fluid that can easily be manufactured from renewable sources such as sugarcane and corn, which is much more sustainable than fossil fuels like gasoline, derived from crude oil. It is often added to gasoline as an additive and denoted by a code to show the percentage of ethanol in the gasoline, such as E10, E15, or E85. This is also known as flex fuel.

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