High-octane fuel is a type of gasoline that has a higher octane rating compared to regular fuel. The octane rating measures a fuel's ability to resist knocking or pinging during combustion, which can occur when the air-fuel mixture ignites prematurely. Higher octane fuels, such as premium gasoline, are often recommended for high-performance vehicles, as they can enhance engine efficiency and power. Using high-octane fuel can improve the performance of certain engines, particularly those designed for it, like sports cars or luxury vehicles. However, for most standard vehicles, using regular fuel is sufficient and more cost-effective. It's important to follow the manufacturer's recommendations for fuel type to ensure optimal engine performance and longevity.