The term 'Gasoline Rating' refers to the octane rating of gasoline, which is a measure of the fuel's ability to resist 'knocking' or 'pinging' during combustion. The higher the octane rating, the more resistant the fuel is to knocking. Octane ratings are typically expressed as a number, such as 87, 89, or 91. Higher octane ratings are usually more expensive, but they can provide better performance and fuel economy in certain engines.