# List of U.S. states by standard octane ratings

Most states do not mandate certain standard gasoline grade octane ratings. In the United States and Canada, octane ratings are in AKI, commonly shown as "(R+M)/2". All states require gas pumps to be labeled with the correct octane level and nearly all states do regular testing to make sure gas stations are in compliance. A minimum 82 octane fuel is recommended for most vehicles produced since 1984. Older cars with carburetors could operate with lower octane fuel at higher elevations. Regardless of legality fuel with an octane rating of less than 82 is generally not offered for sale in most states. However 85 and 86 octane gasoline can still commonly be found in several Rocky Mountain states but availability is declining due to fewer cars with carburetors being still on the road and they are already gone in many states that previously sold it like Alaska, Maine and North Dakota.

## State octane ratings

The octane ratings below are the lowest allowed by law and may or may not reflect the actual levels offered for sale at most gas stations. Ethanol's effect on octane is not considered—these are ratings that are seen at the pump.
| State | Regular unleaded | Mid-grade unleaded | Premium unleaded | Notes |
| Alabama | 87 | 89 | 93 | |
| Alaska | 87 | 88.5 | 90 | |
| Arizona | 87 | 89 | 91 | |
| Arkansas | 87 | 89 | 91/93 | Northwest Arkansas primarily sells 87/89/91 octane. 93 octane is available at select Kum & Go's in the Northwest and Central regions of the state. |
| California | 87 | 89 | 91 | |
| Colorado | 85 | 87 | 91 | |
| Connecticut | 87 | 89 | 93 | 86 octane may be sold if labeled as economy |
| Delaware | 87 | 89 | 93 | |
| Florida | 87 | 89 | 93 | 91 octane premium is sold at select stations alongside 93 octane. |
| Georgia | 87 | 89 | 93 | |
| Hawaii | 87 | 89 | 92 | |
| Idaho | 85/87 | 87/89 | 91 | Octane ratings in Eastern Idaho are 85/87/91 in Western Idaho the octane ratings are 87/89/91. |
| Illinois | 87 | 89 | 91 | 93 is widely available in the Chicago area. Elsewhere in Illinois, 93 is offered at Shell and select other stations. Many fuel stations now offer an 88-octane fuel blend that is 15% ethanol, suitable for use in some gasoline-powered automobiles from model year 2001 and newer. |
| Indiana | 87 | 89 | 93 | |
| Iowa | 87 | 89 | 91 | Many stations will offer "Super Unleaded" 87 that contains 10% ethanol and a more expensive "Unleaded" 87 with no ethanol. 93 is available at select Kum & Go and Murphy USA / Walmart locations. |
| Kansas | 87 | 89 | 91 | All BP Stations offer 93 octane gasoline |
| Kentucky | 87 | 89 | 93 | |
| Louisiana | 87 | 89 | 93 | |
| Maine | 87 | 89 | 91 without ethanol 93 with ethanol | Premium gas must be at least 93 octane if it contains 10% or more of ethanol |
| Maryland | 87 | 89 | 93 | |
| Massachusetts | 87 | 89 | 93 | |
| Michigan | 87 | 89 | 93 | 85 and 86 octane may be sold if labeled as subregular |
| Minnesota | 87 | 89 | 91 | 110 octane fuel may be available at certain locations in southern parts of the state. |
| Mississippi | 87 | 89 | 93 | |
| Missouri | 87 | 89 | 91/93 | Some Phillips 66, Break Time, and Conoco stations sell 91 octane premium. Southwest Missouri in the Ozark Mountains and Mark Twain primarily only sell 87/89/91 |
| Montana | 85.5 | 88 | 91 | |
| Nebraska | 87 | 89 | 91 | |
| Nevada | 87 | 89 | 91 | Eastern Nevada primarily uses 85/87/91 octane ratings. |
| New Hampshire | 87 | 89 | 93 | |
| New Jersey | 87 | 89 | 93 | New Jersey checks for fraudulent labeling of octane ratings. |
| New Mexico | 86 | 88 | 91 | |
| New York | 87 | 89 | 91/93 | 93 is widely available. |
| North Carolina | 87 | 89 | 93 | 91 octane is commonly sold as "premium" in the western, mountainous part of the state. |
| North Dakota | 87 | 89 | 92 | |
| Ohio | 87 | 89 | 93 | |
| Oklahoma | 87 | 89 | 91 | |
| Oregon | 87 | 89 | 92 | |
| Pennsylvania | 87 | 89 | 93 | |
| Rhode Island | 87 | 89 | 93 | |
| South Carolina | 87 | 89 | 93 | lower octane gas can be sold if labeled as "sub-standard" or "sub-regular" |
| South Dakota | 85/87 | 87/89 | 91 | 85 octane must be sold with a warning label displayed at the pump. 85 and 86 octane can be sold as regular fuel only in the counties of Butte, Custer, Fall River, Harding, Lawrence, Meade, Oglala Lakota, Pennington, and Perkins. 87 and 88 can be sold as mid-grade in the previously-named counties. |
| Tennessee | 87 | 89 | 93 | |
| Texas | 87 | 89 | 93 | El Paso, Lubbock, and Amarillo areas have 86/88/91 octane ratings. |
| Utah | 85 | 88 | 91 | |
| Vermont | 87 | 89 | 93 | |
| Virginia | 87 | 89 | 93 | |
| Washington | 87 | 89 | 92 | |
| West Virginia | 87 | 89 | 93 | |
| Wisconsin | 87 | 89 | 91 | 93 widely available |
| Wyoming | 85 | 88 | 91 | |