Is 97 octane gasoline the same as 98 octane gasoline now?

[ChristianMarie]

97 octane gasoline is not the same as 98 octane gasoline now. Here is the relevant introduction about gasoline: 1. Introduction: Gasoline is a volatile and flammable hydrocarbon mixture liquid distilled and cracked from petroleum, which can be used as fuel. It appears as a transparent liquid, is flammable, with a distillation range of 30°C to 220°C. The main components are C5～C12 aliphatic hydrocarbons and naphthenic hydrocarbons, as well as a certain amount of aromatic hydrocarbons. Gasoline has a high octane number (anti-knock combustion performance) and is divided into different grades such as 89, 90, 92, 93, 95, 97, and 98 according to the octane number. Starting from January 2012, the gasoline grades 90, 93, and 97 were revised to 89, 92, and 95. 2. Physical and chemical properties: Gasoline is a colorless to light yellow, easily flowing liquid at room temperature, hardly soluble in water, flammable, with a distillation range of 30°C to 205°C. When the air content is 74～123 grams/cubic meter, it will explode upon encountering fire. The calorific value of gasoline is about 44000 kJ/kg (the calorific value of fuel refers to the heat generated by the complete combustion of 1kg of fuel).

[SanElle]

Not the same thing at all, 97 and 98 octane gasoline are completely different. Previously, China adjusted its gasoline grades, changing 93 and 97 octane to 92 and 95 octane, and also added 98 octane. So, 97 octane is equivalent to today's 95 octane, while 98 octane is a higher-grade fuel. Their main difference lies in anti-knock performance; 98 octane has a higher octane number, making it smoother for engines with high compression ratios, helping to prevent knocking. My car runs fine on 95 octane, and only sports cars or high-performance turbocharged vehicles really need 98 octane. When refueling, make sure to check the grade labels carefully—there's no such thing as 97 octane anymore, so don't fill up with the wrong fuel.

[LaAlex]

97 and 98 octane gasoline are completely different. The previously common 93 and 97 octane ratings have now been replaced by new ratings. 97 basically corresponds to today's 95 octane gasoline, while 98 is a higher-octane option. The main difference lies in the octane rating—98 octane allows the engine to run more smoothly, especially suitable for models with a compression ratio greater than 10:1. For regular family cars like mine, 95 octane is perfectly sufficient. 98 octane is not only more expensive but also offers no noticeable improvement for daily commuting. When refueling, always check the recommended octane rating on the fuel tank cap and don't be misled by the old terminology.

[McCaroline]

97 is not 98. After the gasoline grade reform, 97 has been renamed to 95, while 98 is a newly added premium gasoline. They have different octane ratings, with 98 having stronger anti-knock properties, making it suitable for high-performance engines. For regular cars, 95 is sufficient. For example, my naturally aspirated car would be a waste of money to use 98. However, it's important to note that fuel quality varies by region. During long-distance self-driving trips, it's best to use higher-grade fuel when refueling at local gas stations.