RON

Main article: Octane rating

In Australia, gasoline is unleaded, and available in 91, 95, 98 and 100 Octanes (names of various gasolines differ from brand to brand), fuel additives for use in cars originally designed for leaded fuel are available at most gas stations.

In Canada, the most commonly found octane grades are 87 (regular), 89 (mid grade) and 91 (Premium), using the "(R+M)/2 Method".

In China, the most commonly found octane grade is RON 91 (regular), 93 (mid grade) and 97 (premium). Almost all of the fuel has been unleaded since 2000. In some premium gas stations in large cities, such as Petrol China and SinoPec, RON 98 gas is sold for racing cars.

In Europe, gasoline is unleaded and available in 95 RON (Eurosuper) and, in nearly all countries, 98 RON (Super Plus) octanes; in some countries, 91 RON octane gasoline is offered as well.^{[citation needed]} In addition, 100 RON petrol is offered in some countries in continental Europe (Shell markets this as V-Power Racing [2]). Some stations offer 98 RON with lead substitute (often called "Lead-Replacement Petrol, or LRP).

In New Zealand, petrol is unleaded, and most commonly available in 91 RON ("Regular") and 95 RON ("Premium"). 98 RON is available at selected BP ("Ultimate") and Mobil ("Synergy 8000") service stations instead of the standard 95 RON. 96 RON was replaced by 95 RON, and subsequently abolished in 2006. Leaded fuel was abolished in 1996.

In the UK, the most common petrol grade (and lowest octane generally available) is 'Premium' 95 RON unleaded. 'Super' is widely available at 97 RON and some large brands offer 98 - 99 RON fuel as a premium product costing up to 10% more than standard 'premium' fuel (for example Shell V-Power, BP Ultimate or Tesco 99). Leaded fuel is not widely available. A 102-octane fuel is available in the UK at a limited number of BP stations (for a far higher price than other fuels), for racers and car enthusiasts.

In the United States, all motor vehicle gasoline is unleaded and is available in several grades, which are differentiated by octane rating: 87 (Regular), 89 (Mid-Grade), and 93 (Premium) are typical grades [3]. The maximum octane rating in California is generally 91. Minimum octane levels are often lower in the Mountain States, where regular unleaded can be rated as low as 85 octane.