Car Care

Premium vs. Regular Gas: A Complete Guide for 2021

Close up hand of man pumping gasoline fuel in car at gas station
Close up hand of man pumping gasoline fuel in car at gas station

Wondering if premium gas is worth the premium price? Keep reading to find out when and if you should be using premium gasoline in your vehicle to maintain the best possible engine performance!

What Is Premium Gas?

Gasoline is rated by the level of octane in the fuel mixture. The higher the octane, the more compression the fuel can withstand before detonating. 

This helps prevent engine knocking in high-compression engines that are using a form of forced induction, such as a turbocharger or supercharger.

In simple terms? 

Premium gas is any type of gasoline with an octane rating of 91 or greater. You’ll see this number (usually between 91 and 94) listed on the yellow label at the gas pump under “Premium” or “Super Premium.”

What Is the Difference between Regular and Premium Gas?

Simply put, premium grade gasoline has an octane rating of 91+ while regular unleaded gasoline is generally rated as 87. This is the lowest octane fuel and what most engines are designed to run on.

Which octane levels can be listed as regular, mid-grade, or premium vary by state, but regular gasoline will always be listed as the fuel type with the lowest octane rating. It’s also the cheapest fuel to run on, which is why so many people are asking if premium gas is worth it and whether or not it’s better for your car. After all, paying an extra $0.40, $0.50, or $0.60+ per gallon adds up fast!

However, with smaller, higher compression engines that utilize turbocharging, direct injection, and advanced computer controls becoming more mainstream, many manufacturers are designing vehicles that require the higher octane levels in premium gas. 

Using the proper fuel octane rating ensures that combustion happens when it was designed to happen within your specific vehicle. This goes back to the problem of “engine knock” and how premium gas with higher octane prevents it.

What Is Engine Knocking?

In an internal-combustion engine, fuel should burn in a controlled, even manner. When detonations within the engine are uncontrolled, this produces tiny waves that cause the engine to vibrate and produce a “knocking” sound you can hear. 

This article goes more in depth on what engine knock is and how to fix it, but for now, all you really need to know is that higher octane fuel (premium gas) protects the engine from exploding when it’s not supposed to in high-compression engines.

When Should I Buy Premium Gas vs. Regular?

If you get nothing else from this article, know this: If your manufacturer requires premium gasoline, get it. Period. Otherwise, you’ll end up paying for a host of costly engine problems in your near future.

If your vehicle doesn’t require premium gasoline (91 octane or greater), use whatever is required. This information should be specified on your gas door or inside the owner’s manual. 

Best practice is to always, always, ALWAYS follow the minimum required octane rating from your manufacturer.

What If My Manufacturer Recommends Premium Gasoline, But Doesn’t Require It?

If premium gas is suggested by your manufacturer but not required, go with the minimum octane rating that is required, most likely 87. This will help you save money while ensuring your engine isn’t damaged.

According to the Federal Trade Commission, unless premium gas is required by your manufacturer, don’t bother wasting your money for “enhanced” performance.

“In most cases, there’s no benefit. Higher octane helps only if you have problems with your engine ‘knocking.’” (

Here’s another example that proves premium gas isn’t necessarily better for your car:

Car and Driver tested a Honda CR-V with 87 octane vs. 93 octane fuel. In the premium gas test, the CR-V’s zero to 60 and quarter-mile times were a “tenth of a second slower on the expensive stuff.” 

At 75 mph, the CR-V’s fuel economy went from 27.3 mpg to 27.6 mpg, “a 1 percent improvement for a 21 percent higher cost.” (

One percent better for 21% more money? Not worth it in our books! Save your cash and stick with what works.

When Should I Use Mid-Grade Fuel?

Check your owner’s manual. Different cars require different octane ranges depending on manufacturer’s specifications due to many factors, including timing and ignition advance, the compression ratio of the engine, and others. 

If your particular engine requires mid-grade fuel, then this will be specified on your gas door or owner’s manual, typically as minimum octane level 89.

What Is TOP TIER™ Gas and How Is It Different from Premium Gas?

If you’re looking to get the best short and long-term performance out of your vehicle, you may not need to pay a big premium for gas.

TOP TIER Detergent Gasoline is the highest quality of fuel on the market and only costs about $0.03 more per gallon according to AAA.

TOP TIER gas was developed in 2004 to offer better engine protection from carbon buildup and deposits, which can lead to engine knock, rough idling, reduced fuel efficiency, and more. It’s supported by top automakers, such as Audi, BMW, Mercedes-Benz, and Toyota, who recommend it to preserve original engine performance and reduced emissions.

Unlike premium gas, which refers to a specific octane rating, any grade of gasoline can be considered TOP TIER if it adheres to the stringent standards. Since 1995, all fuel manufacturers are required to have a minimum level of additives to keep engine components clean, improve fuel economy, and improve power.

TOP TIERgasoline contains the highest level of quality additives with enhanced deposit control performance. This new standard is what is known as TOP TIER™.

You can find this top-shelf gasoline at retailers such as BP, Chevron, Costco, Exxon, and more. Check with your local fuel retailer or look for the logo for TOP TIER™ gasoline:

How Can I Raise Fuel Octane Levels Myself?

If you accidentally fill up with regular and your vehicle requires premium, don’t freak out. As a short-term fix, you can add an octane booster (sold at your local auto parts store) to your tank.

You can also drive around and burn off some gas, then put in premium gas to slowly raise the octane level of your fuel. Just don’t make filling up with 87 a habit and your car should be fine.

Bottom Line: Is Premium Gas Better for Your Car?

It depends on your engine and how the manufacturer designed it. 

Here’s an easy rule of thumb:

If your owner’s manual requires your vehicle to run on premium high-octane fuel, then YES! Premium gas is not only better for your car, but it’s a must-have if you want to avoid costly issues down the road.

On the other hand, if your manufacturer doesn’t require premium gas (octane level 91 or higher), then don’t waste your money. Any benefits you see will be minimal compared to the increased cost. Instead, use whatever the minimum required octane level is for your specific make and model. You’ll find this information inside your fuel door or owner’s manual.

One last thing to remember:

If you want to get the most out of your vehicle, running the right fuel is certainly a great place to start. But keeping up with routine maintenance is just as critical! 

The FIXD Sensor and free app is here to help. Not only will it tell you if there are any major problems and translate your check engine light into plain English, but it also tracks maintenance and wear items for you, including oil changes and battery life, so you can keep your car in tip-top shape without having to send yourself reminders or track a spreadsheet.

Click here to learn more about FIXD!

Engines that have a higher-compression engine or are using a form of forced induction, which usually includes a turbocharger or a supercharger, often will require higher octane fuel to prevent preignition (knock) from becoming a problem when the vehicle is under load. If a vehicle’s ECU isn’t programmed to utilize the higher octane fuel with ignition advance etc, the benefit will be minimal.


Wife, mom, Content Manager & Senior Copywriter at FIXD. From the garage to the gym, I love helping people learn and grow. Dream car: ‘69 Acapulco Blue Mustang.

Kate McKnight
Wife, mom, Content Manager & Senior Copywriter at FIXD. From the garage to the gym, I love helping people learn and grow. Dream car: ‘69 Acapulco Blue Mustang.

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    1. It would help if you would have told me if and how I can raise my octane level myself, when I need to.

      1. Hi Ron,

        One way to raise your octane levels by blending high octane fuel with low octane fuel.

        The FIXD Team

        1. One side caviot, I’ve decided to use non ethanol gas this year which is only offered locally as the high octane choice. I’ve seen the damage ethanol causes to my vehicles over the years as well as lab test that confirm my observations.
          I’ve been using non ethanol in all my small engines for years with excellent results. When it comes to aviation fuel, for the personal size planes, any ethanol is not allowed. I can’t speak for the big jets, but I’m sure the same applies.
          Just saying.

        2. How about using alcohol free gasoline?

        3. Very well explained, in clear detailed informations which knowledge to how to live
          and treat my car. However, you never mentioned on V6 Infiniti engine. Thanks

    2. Already knew this 77 year old mechanic owned and operated gas stations , repair shops, Ford, Chevy and other certifications etc. Use the top tier fuel a good deal a the Costco’s and others my turbos yes I use octane boosters!
      Good Info you put out I Appreciate it!

    3. What about using alcohol free gasoline?

    4. Im confused I own a 2009 Cadillac STS Must I use high octane fuel?

      1. Deborah, a web search can answer this if your gas fillup door doesn’t have a sticker or you don’t have the manual. Only if you have the 8 cylinder 4.6 L engine are you required to use premium gas in a 2009 CTS.

      2. Your owners manuel should tell you what octane to run. Usually 87. You could Google it if you don’t have your owners manual.

    5. One of the first things I did was read my Owners Manual…
      I have a 1996 Honda Wagon, a daily driver, a commute car. It’s good on gas. I use Premium, and I fill-up once a week – $30 – because my Manual suggest I do it. Oil to Spark Plugs…I follow it. I want my car (200 Thousand plus miles) to have longevity…so far, so good.

    6. I have a 2002 Jeep Liberty, a relatively older SUV. I use regular unleaded and I do experience engine knocking, will switching to premium reduce the knocking and should I empty my tank before switching?

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