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.

map of the US by premium gas minimum

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[1]
Delaware 87 89 93
Florida 87 [2] 89 93 91 octane premium is sold at select stations alongside 93 octane.
Georgia 87 [3] 89 93 [3]
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 [4] 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 [5] 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[6]
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 [7] 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.[8]
New Mexico 86 88 91
New York 87 [9] 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 [10] 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"[11]
South Dakota 85/87 87/89 91 85 octane must be sold with a warning label displayed at the pump.[12] 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.[13] 87 and 88 can be sold as mid-grade in the previously-named counties.[13]
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

References

  1. ^ "Connecticut Department of Consumer Protection" (PDF).
  2. ^ Florida Administrative Code 5F-2
  3. ^ a b "Fuel & Measures FAQs - Ga Dept of Agriculture".
  4. ^ "Motor Fuel and Petroleum Standards Act". Illinois General Assembly.
  5. ^ http://www.lrc.state.ky.us/kar/302/079/010.htm
  6. ^ "Motor Fuels Quality Act of 1984" (PDF). Michigan Legislature. 2021-12-02. Archived from the original (PDF) on 2021-12-05.
  7. ^ "Frequently Asked Questions".
  8. ^ "New Jersey Weights and Measures" (PDF). NJ Department of Law and Public Safety. Retrieved 7 September 2017.
  9. ^ "2012 New York Consolidated Laws :: AGM - Agriculture & Markets :: Article 16 - (176 - 197-B) WEIGHTS AND MEASURES :: 192-A - Fuel octane labelling requirements".
  10. ^ "Article 33-34: Petroleum and Fuel Products" (PDF). North Dakota Legislative Assembly.
  11. ^ "Code of Laws - Title 39 - Chapter 41 - Gasoline, Lubricating Oils and Other Petroleum Products".
  12. ^ "South Dakota Legislature".
  13. ^ a b "South Dakota Legislature".