What is the Difference Between Gasoline Types?
2 Answers
Different gasoline models: This is due to the varying proportions of certain components, which result in different performance characteristics when used in engines. The significance of the octane rating is that the higher the gasoline's octane number, the stronger its anti-knock properties, and it has no relation to the quality of the fuel. Different gasoline octane ratings: This represents the ratio of the actual gasoline's anti-knock performance to that of standard gasoline. The higher the octane number, the stronger the anti-knock performance. Standard gasoline is composed of isooctane and n-heptane. A higher octane number is not necessarily better; the appropriate gasoline octane should be selected based on the engine's compression ratio. Criteria for selecting gasoline octane in cars: The engine's compression ratio is a core energy-saving indicator in modern vehicles. Engine operation consists of a cyclical process of "intake--compression--combustion--exhaust--intake" in the cylinders. The compression ratio is the ratio of the cylinder volume at the farthest and nearest points of the piston's stroke. To reduce fuel consumption costs, the best method is to increase the engine's compression ratio. Increasing the compression ratio simply changes the piston stroke; the more the air-fuel mixture is compressed, the greater the combustion reaction and the more complete the combustion. However, the compression ratio cannot be easily altered because it must be matched with another indicator: the gasoline's anti-knock performance, also known as the octane number or gasoline rating.
I've been driving for almost ten years, and the most frequently asked question is about the difference between 92, 95, and 98 gasoline. These numbers actually represent the octane rating, which simply indicates the fuel's resistance to knocking. For ordinary naturally aspirated engines, 92 octane is sufficient—my old Jetta ran fine on it for seven or eight years. However, turbocharged cars have higher compression ratios and must use 95 or 98 octane, otherwise, the engine will start knocking. Higher-octane gasoline doesn’t necessarily burn more efficiently or save fuel, but it contains more detergents. Once, I tried saving money by using 92 octane, and the power noticeably dropped. Always check the fuel cap label when refueling—using the wrong grade can damage the oxygen sensor.
