Should a new car use 95 octane gasoline?
3 Answers
The type of gasoline a car should use has nothing to do with whether the car is new or not, but mainly depends on the engine compression ratio. Difference in fuel grades: The biggest difference between 92 and 95 octane gasoline lies in their different octane ratings. The higher the octane number, the higher the corresponding octane value, which means the initial boiling point and dry point of the gasoline are higher, and consequently, the ignition point is higher. Effects of mixing fuels: Compression ratio refers to the volume ratio between the lowest point of the piston and the combustion chamber at the highest point. The higher this ratio, the higher the temperature in the combustion chamber when the piston reaches the top dead center. If the temperature reaches the ignition point of the gasoline before the piston reaches the top dead center, the gasoline will ignite prematurely, leading to what is commonly known as engine knocking. This causes a reverse impact on the piston, resulting in insufficient power, increased fuel consumption, and engine damage. Prolonged exposure to this condition can cause irreversible damage to the engine.
I've been driving for over a decade and often get asked by friends what fuel to use for new cars. The key isn't the octane rating, but rather the recommended grade indicated inside the fuel filler door or in the owner's manual. Some turbocharged engines require 95 octane to prevent knocking, while regular naturally aspirated cars run perfectly fine on 92 octane. Once my cousin filled his new car directly with 98 octane, only to find increased fuel consumption, and later discovered it caused incomplete combustion leading to more carbon buildup. With fuel prices so high now, following the manufacturer's recommended grade is most cost-effective. Of course, if the manual suggests 95 octane, it's better not to use 92 long-term as it can damage the engine. During the break-in period, it's especially important to strictly follow the manual's instructions.
When I first got my car, I also struggled with the fuel choice. 95-octane gasoline has better anti-knock properties and is suitable for high-compression engines, but it's a waste for low-compression models. Remember three things: always check the fuel cap label first, turbocharged German cars usually require 95-octane, while naturally aspirated Japanese cars run fine on 92-octane. Don't believe that higher-octane fuel boosts performance—I tested my own car with both 95 and 92, and the 0-100 km/h acceleration difference was less than 0.5 seconds. The key is to avoid mixing different octane ratings; suddenly switching to 92 when the tank is half full might cause knocking. Just have the mechanic check the spark plugs during regular maintenance.
