In 2008, premium gasoline (greater than 90-octane) accounted for only 8% of refiner gasoline sales but by 2021 that number had grown to 13%. The increased sales of premium gasoline may be driven in part by more vehicles on-road with high compression/high-efficiency engines that require higher octane fuel. Midgrade gasoline comprised less than 1% of total refiner gasoline sales in 2021 replaced by increases in both premium and regular gasoline shares over the last two decades.
Notes: Octane requirements may vary by altitude.
- Premium gasoline - Gasoline having an antiknock index, i.e., octane rating, greater than 90.
- Midgrade gasoline - Gasoline having an antiknock index greater than or equal to 88 and less than or equal to 90.
- Regular gasoline - Gasoline having an antiknock index greater than or equal to 85 and less than 88.
Source: U.S. Energy Information Administration, Refiner Motor Gasoline Sales Volumes, queried October 27, 2022.