Which gas is better 87 or 93?

In most passenger vehicles, 87-octane regular gasoline is sufficient and recommended by manufacturers. 93-octane premium offers higher resistance to knocking and is intended for engines with higher compression or turbocharging, but it does not universally deliver more power or better fuel economy in every car. The best choice depends on your vehicle’s design and driving conditions.

What the octane numbers really mean

Octane rating measures a fuel’s resistance to pre-ignition or knocking, not its energy content. Higher octane helps prevent engine knock in high-compression or forced-induction engines, especially under heavy loads or hot conditions. In the United States, 87 octane is labeled as regular (AKI), while 93 octane is premium; elsewhere, ratings are given in terms of RON or different scales, which can create confusion when comparing fuels across regions.

• Octane is a measure of knock resistance, not horsepower or energy per gallon.


• 87 octane is the standard grade for many cars; 93 octane is a higher-grade option used for specific engines.


• Using higher-octane fuel than your engine requires rarely yields a noticeable improvement in performance or efficiency}


• Modern engines with knock sensors may adjust timing to run on lower-octane fuel, but advisories exist in the manual for premium use in certain situations


• Damage from using too-low octane can occur in engines designed for higher octane, due to knocking

In summary, octane rating relates to knock resistance and engine design compatibility. The energy content of 87 and 93 octane fuels is broadly similar, so the main question is whether your engine needs the higher resistance to detonation.

Which grade is better for your car: 87 or 93?

To determine the right fuel grade for your vehicle, rely on the manufacturer’s guidance and your driving context. Most everyday cars run best on 87 octane, while some high-performance or turbocharged engines require or recommend 93 octane to prevent knocking under load. Costs and benefits should be weighed; premium fuel costs more per gallon and may not deliver noticeable gains in a car designed for regular fuel.

Before considering the next list, note the common scenarios where higher octane might matter. Here are guidelines to help decide when 93 octane could be worth it:



• Engine requires premium fuel as specified in the owner's manual or fuel cap sticker


• Engine experiences knocking or pinging under heavy acceleration, towing, or hot weather


• Vehicle uses a turbocharger, high-compression design, or performance-tuned settings


• Consistently driving in conditions that stress the engine (hilly terrain, high loads, or high speeds)


• Warranty or maintenance notes suggest premium fuel for optimum performance

In practice, using 93 octane in a car that is designed for 87 octane does not guarantee better acceleration or fuel economy; any potential gains are often small or situational. If your car runs smoothly on regular fuel and you don’t encounter knocking, sticking with the recommended grade is usually the most economical choice.

Cost considerations and practical tips

Choosing between 87 and 93 octane is not just about performance; it’s also about value. Here are practical pointers to consider:

• Compare price per gallon and estimate cost per mile to see if premium fuel is worth the expense


• Follow the car’s manual or the fuel door label—never substitute premium if regular is advised


• If you don’t notice improved performance or quieter operation with premium, regular is typically the better option


• Towing, hot climate, and sustained high-load driving can tilt the balance toward premium in some engines


• If you suspect knocking, have the engine inspected; don’t rely on premium as a fix for mechanical issues

The key takeaway is to use the grade recommended for your vehicle. Premium fuel offers knock resistance for specific high-performance or high-compression engines, but it rarely yields a universal performance boost for cars designed for regular fuel—and it comes with a higher price tag.

Summary

Octane ratings indicate knock resistance, not energy content. For most cars, 87-octane regular gasoline is sufficient and economical. 93-octane premium is intended for engines that require higher resistance to detonation to avoid knocking, such as certain high-compression or turbocharged engines. Always follow the manufacturer’s recommendation, consider your driving conditions, and weigh the cost against any potential performance gains. In many cases, there is no meaningful benefit to using premium fuel unless your vehicle specifies it or you notice knocking under load.

Do you get better gas mileage with 93?

Yes and no. Putting high octane in an engine that requires 87 octane will not get you better fuel economy. However, if you put 87 octane in an engine that requires 93 octane, you will lose fuel economy. The reason is that engines that have a higher octane rating tend to have a higher compression ratio.

Why do people use 93 gas?

A higher-octane rating means the fuel is better balanced and stabilized against spontaneous combustion, which can cause knocking and damage to a car engine. Premium gas may also contain additional, higher-quality additives compared to regular gas.

Does 93 gas clean your engine?

No, 93 octane gas itself does not clean your engine; that is a myth, as octane rating indicates a fuel's resistance to detonation, not its cleaning properties. All gasoline, regardless of octane, contains detergents to help keep engines clean, a requirement by the EPA. However, some premium fuels may have more or different cleaning agents as a marketing point, and the detergents in the blend can offer some cleaning benefits, especially for engines designed to run on higher octane fuel. 

• What octane is for: The octane rating (like 93) measures a fuel's resistance to "knocking" or "pinging" during combustion. Using a higher octane than your engine is designed for will not provide any cleaning benefit. 
• What does the cleaning: All gasoline has detergents that help clean the engine and its components. 
• Premium vs. Regular: Some premium gasolines are marketed as having more cleaning agents, which could offer some benefit, but this is separate from the octane level. 
• Check your manual: The best way to know what fuel is right for your car is to check your owner's manual. Using the manufacturer-recommended octane level is ideal for engine health and performance. 

Is it better to run 93 instead of 87?

No, it is not better to run 93 octane instead of 87 unless your car's engine is specifically designed for higher octane fuel. For most cars that run on 87, using 93 octane is a waste of money as it provides no performance benefits, such as better mileage or a faster engine. The owner's manual for your vehicle will state the minimum octane required. 
When to use 93 octane

• High-compression engines: Some high-performance, turbocharged, or high-compression engines require 93 octane to prevent engine knock and ensure optimal performance. 
• After a tune: If you have modified your car's engine with a performance tune, you may need 93 octane to take full advantage of the tune, as it can allow for more aggressive engine timing. 

When using 87 is sufficient

• Check your owner's manual: If your owner's manual specifies 87 octane as the recommended or minimum grade, there is no need to use a higher octane. Using 93 will not make your car run cleaner, faster, or get better gas mileage. 
• You are not tuned: For a stock engine, higher octane fuel will not provide any significant advantage. 

Why running the wrong octane is a risk

• Using lower octane than required: If your car requires 93 octane and you use 87, you risk engine knock, which can cause long-term damage. 
• Using higher octane than required: If your car is designed for 87, putting 93 in is a waste of money. Nothing good will happen, and in some cases, it may not even burn as thoroughly, potentially leading to a slight decrease in performance.