Have a car that doesn't need premium fuel? Don't buy it at the pump.
Americans wasted $2.1 billion last year on premium fuel for cars designed to run on regular gasoline, according to a new study from AAA. Despite common misconceptions stemming from its higher price tag and elite-sounding name, premium fuel doesn't provide any benefits for engines that aren't built for it, experts say.
"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, in a news release Tuesday. "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."
Higher octane gasoline is able to withstand higher pressures inside the engine than cheaper, regular gasoline. But the pressure inside engines that are designed to run on regular gasoline isn't great enough to require the higher octane rating, rendering premium fuel useless.
"Premium gasoline is specifically formulated to be compatible with specific types of engine designs, and most vehicles cannot take advantage of the higher octane rating," said Megan McKernan, manager of the Automobile Club of Southern California's Automotive Research Center. "Using premium fuel in a vehicle designed for regular is like throwing dollars out the window while you are driving."
Although the majority of vehicles – 70 percent – run on regular gasoline, approximately 16.5 million drivers put premium fuel in their cars at least once last year, AAA found. When you consider that premium costs, on average, about 50 cents a gallon more than regular, which adds up to $2.1 billion wasted.
Drivers looking to upgrade their gasoline should seek out fuel of a higher quality, not a higher octane level, Mr. Nielsen said. A study published by AAA in July found that using higher quality gasoline results in significantly fewer engine deposits, increases vehicle performance, and improves fuel economy.
"AAA was surprised to learn the extent to which detergent additives impact gasoline quality," Nielsen said in July. "As advertised, tested TOP TIER gasolines kept engines remarkably cleaner than other fuels we tested."
On the flip side, some of the 16 percent of American drivers whose high-performance vehicles are meant to run on premium gas may wish to downgrade to regular due to the price difference. But the car website Edmunds.com advises car owners hoping to save some money to consult their owner's manual. If the vehicle is described as "premium recommended," it's safe to try switching to regular gasoline. But if your vehicle is "premium required," it's best to stick to high octane.