Does premium gas give you better mileage

Most cars take regular, while others require premium. The difference between these two grades of gasoline isn’t completely obvious, which has led to some misguided spending at the pump. If you’re not sure what you should be filling up your car's tank with, read on. Your wallet might thank you.

So, what's the difference between premium and regular gas?

Regular gas is rated at 87 octane in most states, while premium gas is often rated higher at 91 or 93. Fuel with a higher octane rating can stand up to higher compression before it detonates. Essentially, the higher the octane rating, the lower the likelihood that detonation happens at the wrong time. On occasion, this occurrence will likely not harm your vehicle. However, if it happens frequently it may quicken the decline of your engine's performance. 

Engines with high compression ratios or turbochargers often require high octane fuel found in premium gas for optimal performance and fuel efficiency. However, the majority of cars on the road today are optimized to run on regular gas.

If your car doesn’t require premium, fill up with regular.

Why pay good money for something you don’t need? Premium gasoline costs about fifty cents more a gallon than regular and has no positive or negative effect on vehicles that can’t take advantage of it. In a consumer notice, the Federal Trade Commission, notes: “In most cases, using a higher-octane gasoline than your owner’s manual recommends offers absolutely no benefit. It won’t make your car perform better, go faster, get better mileage or run cleaner.”

The detergent additives in your gasoline are far more important than the octane level, as they help clean your engine and optimize performance. Each retailer offers a different blend of additives, used across all grades. For example, you can find Chevron’s Techron in both their regular and premium gas.

When it comes to additives, some hold themselves to a higher standard. BMW, General Motors, Honda, Toyota, Volkswagen, and Audi helped create the Top Tier Gasoline standard, which mandates a higher-percentage of detergent additive than EPA minimum requirements. They claim that lower concentrations of detergent additive can leave more deposits on engine components, including fuel injectors and intake valves. This, in turn, can lower engine performance and increase emissions.j

If your car requires premium, fill up with premium.

Engines with a high compression ratio typically require higher octane fuel to achieve its intended level of performance, fuel efficiency and emissions. If your car requires premium gas, don’t skimp out. While you might save money on gas, your car will be less powerful and fuel-efficient. This can make a huge difference in vehicles with available turbocharged engines.

What if your car requires premium gas and it isn’t available? While older vehicles may be susceptible to engine knock when running on low octane fuel, modern ones are equipped with sensors monitored by the engine's computer to help prevent knock—and by extension, engine damage. Your car will probably be fine running on regular once in a while, as the engine's computer can adjust the ignition timing, but we don’t suggest putting it to the test on a regular basis.

When you use a lower grade of fuel than what’s recommended or required, a modern vehicle’s ECU (Electronic Control Unit) can account for different octane levels and adjust accordingly. There’s a good chance your horsepower and MPG will go down while CO2 emissions go up. You might save money on gas, but in this situation, you get what you pay for.

If your car only recommends premium, the choice is yours.

With certain vehicles like the Ford F-150 and Mazda MX-5 Miata, automakers recommend premium gas but don’t require it. Research by AAA found that these vehicles saw a slight increase in performance and fuel economy using premium gas. For those who drive a luxury or performance vehicle, premium gas can help emphasize your vehicle’s intended characteristics. 

But if your owner’s manual says “premium fuel recommended,” you can safely run on regular. Depending on what and how you drive, commuters looking to get from Point A to Point B may not notice the difference or care. At the end of the day, it all comes down to your preference. Your car, your rules.

Need some fuel-friendly vehicle choices?

With gas prices on the rise, it can be tough to research all the vehicles currently on sale. To make things easier check out these vehicle picks that are easy on gasoline or use none at all! Also be sure to check out these gas-saving tips.

High-octane gasoline is touted as the best, thanks to the additives in it and the purity of the fuel. 

Vehicles, such as Mazda 6 and Ford Escape offer the best performance running on 93-octane gasoline, but they can run efficiently on 87-octane fuel. 

Automakers sell the idea that using premium gas will help your car perform better. 

But, you will have to pay about $0.59 more for every gallon of gas you buy. Is this extra cost worth it?

Do You Get Better Mileage With Premium Gas?

Premium gas does not give you better fuel economy than regular gas. Premium gas gives more power when burnt, and it works great for performance cars. To make the gas premium, companies have to add ethanol, which has lower energy and might actually reduce fuel economy in a vehicle that is not engineered to use it. 

There are some additives that might actually increase the fuel economy of your engine.

If there is an increase or a reduction in fuel economy, it will be so slight that you will never tell the difference. 

This slight increase cannot be a justification to go for premium gas. 

The octane rating of gas does not affect its energy content. 

If you buy premium gas, it only means that your engine will have greater resistance to knock. 

It means that if there is early combustion, which happens in high-performance vehicles, your vehicle will resist the pressure created in the cylinder. 

Read on the learn more about high-octane or premium gas. 

What Happens If I Don’t Put Premium Gas In My Car?

Is premium gas required for your car, truck, or SUV, or does the manufacturer just recommend it? Today manufacturers create advanced engines. 

This means that even if the automaker recommends that you use premium gas, the vehicle will still run well on regular gas. 

There will be no significant effects on the performance of your vehicle when you use regular instead of premium gas. 

The difference in performance may only be half a second when accelerating from 0 to 60 mph.

A driver will not notice any differences in performance. 

A while ago, drivers would buy a tank of premium gasoline hoping that it would clean the engine.

During those days, premium gas had more detergents than regular gas, and it had more engine cleansing power than regular gas. 

Today, because of government regulations geared at cutting down emissions, all gasoline companies add some additives to reduce pollution and protect the engine of the vehicle. 

If you pick regular gas, you are assured there are enough additives to clean your engine. 

Premium gas is only needed for cars that “require” high-octane fuel. 

Some of the vehicle models that may require high-octane fuel for their performance vehicles include:

• Alfa Romeo Stelvio
• Aston Martin DB11
• BMW 7 series and i8
• Cadillac CTS and XTS
• Chevrolet Corvette
• Infiniti Q70
• Jaguar F-Pace and F-Type
• Lexus NX 300 and GX 460
• Mercedes-Benz CLA-class and GLA-class
• MINI Hardtop 4 Door
• Nissan 370Z
• Volvo S60 and XC60 
• Subaru WRX
• Porsche Cayenne and 911

For the models above, only specific years require premium gasoline. 

Check the vehicle manual to know whether your vehicle requires premium gasoline or the manufacturer just recommends it.

If the vehicle requires premium gasoline, you should not use regular gas as this can void your engine warranty. 

What happens when you use regular gas for a vehicle that requires premium gas? There will be more engine knocking. 

Lower octane gas (regular gas) burns quicker than higher octane gas (premium gas), which means that it needs less energy to ignite. 

The quick-burning increases the tendency to knock when under the high-pressure environment in the cylinders. 

Knocking causes small explosions in your cylinder, which can affect the normal operations of your entire engine. 

Engine knocks can cause costly engine damage that will prompt an expensive engine repair. 

Even if you want to save a few dollars at the pump, always buy premium gas if a vehicle requires it. 

However, if your vehicle does not require premium gas, using it will have no significant increase in vehicle performance or fuel economy. 

How is Premium Gas Different from Regular Gas?

The octane rating on regular gas in most states is 87. 

The rating on premium gas is higher, at 91 or 93. 

Premium fuel is able to withstand high compression before detonating. 

As the octane rating goes up, the possibility of the fuel to detonate reduces.

If detonation occurs, it will not harm the vehicle or affect its performance. 

However, if the detonation occurs frequently, it will affect the performance of your vehicle.

Premium gas is ideal for high compression ratio engines or turbochargers.

In such an engine, the premium gas offer enhanced performance. 

Most of the cars today run well on regular gas. 

When is Using Regular Gas Recommended?

You should use regular gas for all cars that do not require premium gas – that is on most cars on the road today. 

Check your user manual to see if your vehicle requires or recommends premium gas. 

According to Trade Commission, using a higher-than-required gasoline octane rating does not offer you any benefits. 

Your vehicle will not drive faster, will not have better gas mileage, and will not run cleaner. 

Your vehicle needs the detergent additives in the gasoline more than it needs the octane levels. 

Detergent additives increase the cleansing power of the gas to keep your engine clean and enhance its performance. 

Gas companies use a blend of additives across the grades of all they offer. 

The EPA has set the minimum additives requirements for gasoline sold in all gas stations. 

Some automakers require that gas meets a higher standard than the EPA-set standard – this is known as the Top Tier gasoline standard. 

Top Tier gasoline contains concentrated amounts of detergents to help clean the engine better. 

According to these automakers, a lower concentration of detergent additives can still leave deposits in the components of the engine. 

These components can then clog intake valves and affect fuel injectors and increase emissions and lower engine performance. 

Will Regular Gas Damage the Engine of My Car?

If you have a new car, it is less likely that regular gas will damage its engine even if it requires premium gas. 

However, if you have an older engine, it may not have the sensors or the systems to prevent knocking. 

For older engines, the only way to prevent knocking was to vary the octane rating. 

The engine control systems in modern engines adjust the timing of the engine ignition to ensure there is no knocking. 

These sensors and other electronics offer flexibility to motorists on which gas they use. 

Lower octane fuel does not allow any ignition advance during situations that need fast acceleration. 

With more ignition advances, the spark plugs fire sooner and create more power, allowing the vehicle to accelerate faster. 

The engine will not make as much power with regular gas as it does with premium gas, leading to a slower acceleration in vehicles that require premium gas. 

Drivers will not notice the loss in performance unless they are driving turbochargers. 

When used in vehicles that require it, the vehicle will experience better acceleration speeds or when you need to change lanes on the highway. 

Closing Thoughts

Is premium gas worth the price? You can go for premium gas if the vehicle requires it, but if it doesn’t, buying it does not give you any value for your dollars. 

There are adverts on the benefits of premium gas, but some of the touted benefits are available with regular gas too. 

Why go for premium gas if you do not need it? According to AAA, there may only be a slight performance difference in some cars if you use premium gas. 

You may never notice the difference in performance, so unless you have a performance car, stick to regular gas. 

How much more mileage do you get with premium gas?

Will I get better gas mileage with higher octane gas?