What is the difference between unleaded and premium gas

Should You Get Premium Gas For Your Vehicle?

Whenever you fuel up your RV, you get to choose between regular unleaded and several grades of premium gas. All the marketing hype around higher grades of fuel can have you wondering if the upgrade to premium gas is worth the extra money. After all, even regular gas isn’t cheap anymore. 

If you choose more expensive premium gas, you probably do so believing premium gas will do several things:

• Premium gas will help your RV or truck run better
• Premium fuel will help the environment by reducing emissions 
• Using premium gas will result in a better fuel economy

When you buy premium gas, are you really getting the benefits you pay for? We took a look at unleaded regular vs premium gas and found some things that may surprise you.

What is the difference between unleaded and premium gas?

According to the US Energy Information Administration, regular and mid-grade unleaded gas ranges between octane levels of 87 and 90. Premium means gas that has an octane level of 91-94.

Octane ratings are measures of fuel stability. These ratings are based on the pressure at which a fuel will spontaneously combust (auto-ignite) when in a test engine. You can read more about regular unleaded and premium gas octanes on the US EIA website by clicking here.

Besides the octane difference, you’ll pay a lot more for premium. Premium costs as much as .70 cents per gallon more than regular unleaded gas. Some fuel manufacturers also add additional detergents to their premium blends. According to the Federal Trade Commission, all gasoline sold in the USA has to have detergent in it. But is there really any difference for most vehicles?

In 2015, CBC journalists hired experts at CATI Laboratories to do extensive testing of regular unleaded vs premium gas on a Chevrolet Cruise passenger car. They tested engine performance, fuel economy, and emissions quality using CATI’s laboratory equipment. Surprisingly, when they fueled up the car with premium gasoline, testers found no difference in either performance or fuel economy.   

The laboratory analysts also found higher hydrocarbon emissions (due to inefficient fuel combustion) when premium gas was used. In addition, one expert noted that the processes used in the manufacturing of premium fuels could actually harm the environment more than those used to produce regular unleaded gasoline.

AAA has also done extensive testing and concluded that US drivers waste over $2 bilion annually on premium gas.

“Drivers see the ‘premium’ name at the pump and may assume the fuel is better for their vehicle,” said John Nielsen, AAA’s managing director of Automotive Engineering and Repair. “AAA cautions drivers that premium gasoline is higher octane, not higher quality, and urges drivers to follow the owner’s manual recommendations for their vehicle’s fuel.”

AAA

When do you need to use premium fuel?

Not all vehicles benefit from the use of higher octane premium fuel. However, some vehicles come with a recommendation from the manufacturer to use premium gas. Some vehicles were designed to perform at their best on premium gasoline. If your vehicle’s manufacturer recommends premium gasoline, your vehicle’s electronic timing system was designed to run at its best on higher octane fuels. However, not many vehicles need high octane fuel.

If your vehicle’s manufacturer doesn’t recommend premium fuel, your car, truck, or SUV will run perfectly on regular gasoline. If you are unsure what grade of gas your vehicle manufacturer wants you to use in your vehicle, check in your owner’s manual. All manufacturers specify the fuel octane level that your RV or truck will perform best with. 

Did you lose your manual? No worries. Most vehicle manufacturers have it available online to download.

Conclusion

Most vehicles won’t get a cleaner engine, better performance, better fuel economy, or lower emissions when they are fuelled with premium fuel. However, there are a few vehicles that need to have high octane fuel. These are nearly always high-performance vehicles. If you drive one of these, you’ll need to spend the extra money for premium gasoline to keep your car running as it should. The rest of us can all have a big sigh of relief because we can safely fuel up with regular unleaded. 

After all, prices for regular unleaded gas are already high enough! Spending an extra .70+ cents per gallon for premium is just getting hosed at the pump. 

Eliminate RV fuel anxiety by planning every fuel stop in advance, before your RV trip begins. By using RV LIFE Trip Wizard to plan your trips in detail, you’ll know exactly when and where you will need fuel for your RV or truck. You can also vet those fuel stops with satellite and street view to make sure you can get in and out safely, and back on the road.

Related articles:

• 12 Ways To Improve Your RV Gas Mileage
• The Best Diesel Fuel Discounts For RVs
• Where Is The Cheapest Gas In The US?

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