Most U.S. states do not mandate specific gasoline octane ratings. In the United States and Canada, octane is measured using the Anti-Knock Index (AKI), commonly shown as " …

Jun 24, 2025 · This guide explains the different octane ratings for fuel found at gas stations, why some types of gasoline cost more, and which gas you should use for the car you’re buying or …

Nov 17, 2022 · The octane number is actually the simple average of two different octane rating methods— motor octane rating (MOR) and research octane rating (RON)—that differ primarily …

Octane rating is the measure of a fuel's ability to resist "knocking" or "pinging" during combustion, caused by the air/fuel mixture detonating prematurely in the engine. In the U.S., unleaded …

Feb 21, 2024 · It's a hydrocarbon molecule that gives gasoline the ability to resist detonating prematurely in the engine, which causes engine knocking or pinging during combustion. An …

Gasoline grades from RON 87 to RON 97 differ in octane rating, price, and suitability for different engines. Octane rating affects fuel combustion quality, engine knocking, and fuel efficiency.

Octane rating is a measure of a fuel's ability to resist ‘knock.’ The octane requirement of an engine varies with compression ratio, geometrical and mechanical considerations, and …

Sep 28, 2023 · Every time I fill up a car at the gas pump, I’m met with three different fuel choices with varying levels of octane: 87, 89, and 93 (or 91/92). These different octane levels are …

In the United States, unleaded fuel grades are defined by the “octane” rating. The octane rating, the number on the yellow sticker on the gas pump, is listed as the anti-knock index (AKI). The …

Learn how gasoline octanes are different and understand what octane to use in your vehicle.