Tests show premium fuel benefits some vehicles, but comes at a high cost
12 December 2017
Do you buy premium gasoline when you don’t need to? Some motorists think they are doing their car a favor, but AAA released new research that shows paying-up for premium may not be worth the extra money.

While some vehicles are designed to run on and require premium octane gasoline, others simply recommend it. So AAA set out to determine the effects of using premium gasoline in vehicles that recommend it, and whether the benefits in fuel economy and horsepower are worth the higher price at the pump.

The Price of Premium
  • According to national averages, the price difference between regular and premium gasoline is approximately 20 to 25 percent, or 50 cents per gallon.
  • Yesterday, the North Dakota state average price for a gallon of regular was $2.50 vs. $2.95 for premium.
Putting Premium Fuel to the Test
  • AAA tested a variety of vehicles that recommend, but do not require the use of premium (91 octane or higher) gasoline.
  • A series of tests were conducted to determine whether the use of premium gasoline resulted in Improved fuel economy or Increased performance (horsepower).
  • Since drivers of these vehicles are unlikely to see any benefit from using premium gasoline during typical city or highway driving, a combination of laboratory and on-road tests were performed to simulate extreme driving scenarios such as towing, hauling cargo and aggressive acceleration.
  • Test vehicles included a Ford Mustang GT, Jeep Renegade, Mazda MX-5 Miata, Cadillac Escalade ESV, Audi A-3, and Ford F-150 XLT.
Key Findings
  • Most vehicles showed a modest improvement in fuel economy and performance.
  • Fuel economy for test vehicles averaged a 2.7 percent improvement. Individual vehicle test result averages ranged from a decrease of 1 percent (2016 Audi A3) to an improvement of 7.1 percent (2016 Cadillac Escalade).
  • Horsepower for test vehicles averaged an increase of 1.4 percent. Individual vehicle test result averages ranged from a decrease of 0.3 percent (2016 Jeep Renegade) to an improvement of 3.2 percent (2017 Ford Mustang).
  • Premium gasoline costs 20-25% more than regular.
  • The fuel economy improvements recorded during AAA testing do not offset the potential extra cost to purchase premium gasoline.
"Sometimes consumers think they are giving their vehicle a boost by buying a higher-grade gasoline than what is required,” said Gene LaDoucer, North Dakota spokesman for AAA – The Auto Club Group. “AAA already proved that there is no benefit to using premium gasoline in cars designed to run on regular. Now we can confidently say that unless the vehicle manufacturer requires it, or you drive in demanding conditions, motorists who buy premium are likely wasting money at the pump."

Premium Gas - Recommended vs. Required
  • Last year, nearly 1.5 million new vehicles sold in the United States recommend, but do not require, premium gasoline.
  • The trend toward recommending or requiring higher-octane fuel continues to rise as manufacturers work toward meeting stringent CAFE (Corporate Average Fuel Economy) standards.
“There’s no question that higher-octane premium fuel has the potential to boost a vehicle’s fuel economy and performance; however, engines have to be calibrated to require that fuel to see the full benefit,” said LaDoucer. “Based on AAA’s testing, vehicles that only recommend premium gasoline can’t take full advantage of higher octane fuel and, as a result, the benefit that comes from upgrading to premium gasoline may not offset its high cost.”

AAA Recommends:
  • Always follow the vehicle owner’s manual to determine which type of gasoline is recommended and/or required for your vehicle. Vehicles that require premium-grade gasoline should always be fueled with the higher octane gasoline.
  • Drivers of vehicles that recommend, but do not require, premium-grade gasoline should consider their driving habits, the potential benefits and the costs associated with using higher octane fuel.
  • If your engine makes a “pinging” or “knocking” sound when using regular fuel, especially in a vehicle that recommends premium fuel, a higher octane gasoline may resolve the issue, but it’s a good idea to have the vehicle checked by a reputable repair shop.
  • Drivers who choose to use premium fuel should shop around for the best price, as it varies significantly between gas stations in any given city. The AAA Mobile app can help drivers identify the least expensive premium-grade gasoline in their area.
  • Drivers looking for a higher quality fuel should select a TOP TIER™ gasoline. Previous AAA research found that gasoline meeting TOP TIER™ standards resulted in 19 times fewer engine deposits than non-TOP TIER™ fuel.
Higher Octane Does Not Mean "Higher Quality"
  • AAA found no benefit to using premium gasoline in a vehicle that only requires regular-grade fuel.
  • In a study released last year, AAA found that consumers wasted nearly $2.1 billion dollars fueling vehicles with higher-octane gasoline.
  • Drivers seeking a higher quality fuel for their vehicle should consider using one that meets Top Tier standards. Previous AAA research found it to keep engines up to 19 times cleaner.
  • The study noted the difference in fuel quality was dependent on the various detergent packages in gasoline, which vary by retail brand.
Daily national, state, and metro gas price averages can be found at Gasprices.aaa.com. Motorists can find the lowest gas prices on their smartphone or tablet with the free AAA Mobile app. The app can also be used to map a route, find discounts, book a hotel and access AAA roadside assistance.


About The Auto Club Group
The Auto Club Group (ACG) is the second largest AAA club in North America.  ACG and its affiliates provide membership, insurance, financial services and travel offerings to over 9.4 million members across eleven states and two U.S. territories including Florida, Georgia, Iowa, Michigan, Nebraska, North Dakota, Tennessee, Wisconsin, Puerto Rico and the U.S. Virgin Islands; most of Illinois and Minnesota; and a portion of Indiana.  ACG belongs to the national AAA federation with more than 57.7 million members in the United States and Canada and whose mission includes protecting and advancing freedom of mobility and improving traffic safety. Motorists can map a route, identify gas prices, find discounts, book a hotel, and access AAA roadside assistance with the AAA Mobile app for iPhone, iPad and Android. Learn more at AAA.com/mobile. AAA clubs can be visited on the Internet at AAA.com.