If the manufacturer doesn't require premium gas, don't put it in your car.
That's according to a AAA study, which found drivers in the United States wasted more than $2.1 billion over the past year by using premium fuel when their vehicle is designed to run on regular gas.
Seventy percent of vehicles being driven in the United States are designed to use regular fuel, AAA says, but roughly 16.5 million drivers are putting premium gas in their cars when they don't need to.
This can add up to motorists paying hundreds of dollars more a year, the Federal Trade Commission says. A gallon of premium gas in Minnesota can cost up to 40 cents more than a gallon of regular, according to AAA's website.
Premium doesn't mean higher quality
Not only is premium gas more expensive, but there's really no benefit, AAA's study found, with the agency noting premium doesn't mean higher quality.
Premium actually means there's a higher octane rating in the fuel (usually 92 or 93). An octane rating measures a fuel's ability to resist "engine knock" (that rattling or pinging sound during combustion), the Federal Trade Commission says, and certain vehicles are designed to use fuel with higher octane levels to prevent damage to the engine.
"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," Megan McKernan, manager of the Automobile Club of Southern California’s Automotive Research Center, said in the news release.
Buy Top Tier gas instead
If you're looking for a higher-qualify fuel, AAA suggests filling up with a Top Tier gasoline instead. Not only will it save you money over buying premium gas when you don't need it, but it's also proven to increase the performance of your vehicle and improve fuel economy, AAA says.
To find out what type of gas your vehicle needs, the Federal Trade Commission suggests checking your vehicle owner's manual. And remember, octane levels for premium and regular fuels can vary across the country.