Many Americans are “wasting” more than $2.1 billion each year by choosing premium gasoline over regular gas at the pump, the American Automobile Association announced last week. According to a research report issued by the organization, many Americans are making the choice to buy more expensive premium gasoline, when their vehicles are designed to do just fine with regular gas.
“After using industry-standard test protocols designed to evaluate vehicle performance, fuel economy and emissions,” the organization said in a news release, “AAA found no benefit to using premium gasoline in a vehicle that only requires regular-grade fuel.”
In a partnership with the Automobile Club of Southern California’s Automotive Research Center, AAA reported that it tested 87-octane (regular) and 93-octane (premium) gasoline in vehicles equipped with a V-8, V-6 or I4 engine designed to operate on regular-grade fuel. The test involved using a dynamometer, which places cars on a treadmill, and running them while hooked up to a variety of sensors. According to a news release about the findings, there was no significant increase in efficiency in any category.
“AAA’s tests reveal that there is no benefit to using premium gasoline in a vehicle that requires regular fuel,” said Megan McKernan, manager of the Automobile Club of Southern California’s Automotive Research Center. “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.”
This news may be welcome for many drivers, who grew up thinking that premium gas was better for their cars than regular. There can be significant price differences between the two grades of fuel, and drivers might think the term “premium” means “better.” That’s not necessarily the case.
Of course, once upon a time, it was true. Our dads taught us that premium was better on some types of engines, and they were right. Splurging on premium every now and then was a good idea because it contained additives to help clean the engine, and many of us got into that habit. But today, according to many experts, most grades of fuel have additives to protect engines and cut pollution. In addition, today’s engines are “smarter,” equipped with technology that can make adjustments for lower-grade fuels and reduce the “knock” or “ping” older engines might produce when using lower grades of gas.
“In the old days, engines could not adjust to fuels with varying octane ratings. Use the wrong fuel and the engine would knock or “ping” audibly because the gas exploded prematurely,” noted the automotive site Edmunds.com. “This knocking damaged internal engine components over time.”
But Edmunds notes that today’s systems “can compensate for low octane by monitoring knock activity and adjusting ignition advance to avoid knocking. This sophisticated electronic capability effectively tunes the engine on the fly and gives drivers more flexibility in the grade of fuels that they can safely use.”
“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.”
There are, of course, some exceptions. Some higher-performance engines are built to use higher grades of gas. While using regular gas every now and then in these engines is not likely to do harm, sticking with the manufacturer’s recommendation can avoid problems later. And many older vehicles will perform better using higher-octane gasoline. If you’re unsure, check with your mechanic.
If you’re still not convinced, or want to see if there’s a difference in your vehicle in which premium is recommended, Edmunds recommends you conduct your own study.
Monitor your fuel economy and performance over at least two tanks of premium gas. “Record the trip mileage, gallons used, fuel price and octane rating in a notebook or in an app,” Edmunds suggests. “If your car has an onboard fuel economy meter, make sure you reset it when filling up. Then, fill up on the same number of tanks of regular gasoline and record all the same data. Finally, compare the results. You’re looking for a drop-off in fuel economy or a sense that the car is slower or hesitant under strong acceleration.”