The price gap between premium and regular gasoline in the United States has widened to nearly $1 per gallon, the largest in decades. Despite the higher cost, demand for premium fuel continues to grow. Experts, however, say most drivers are paying extra without receiving meaningful benefits.

According to the U.S. Energy Information Administration, the price difference between premium and regular gasoline has steadily increased over the past 20 years. While refining premium fuel has become somewhat more expensive, wholesale price differences have risen far less than retail prices, suggesting gas stations are capturing much of the additional profit.

Demand has increased partly because more new vehicles recommend or require fuel with an octane rating of 91 or higher. At the same time, many motorists mistakenly believe premium gasoline improves engine performance, fuel economy, or engine longevity. Studies by the American Automobile Association (AAA) have found little or no benefit for vehicles designed to run on regular gasoline.

Automotive experts emphasize that octane measures a fuel's resistance to engine knocking rather than its overall quality. Drivers should follow their vehicle manufacturer's recommendations: cars that require premium fuel should always use it, while those that merely recommend it can generally operate safely on regular gasoline, although some performance may be reduced.