What Are the Differences Between Gasoline Types?
2 Answers
Different gasoline models: This is due to varying proportions of certain components, which result in different performance characteristics when used in engines. The octane rating indicates that the higher the gasoline's rating, the stronger its anti-knock properties, but it has no relation to fuel quality. Different gasoline grades: This represents the ratio of the actual gasoline's anti-knock performance to that of a standard gasoline. The higher the grade, the stronger the anti-knock performance. Standard gasoline is composed of isooctane and n-heptane. A higher grade is not necessarily better; the appropriate gasoline grade should be selected based on the engine's compression ratio. Criteria for selecting gasoline grades for 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." 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 only changes the piston's 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, as it must align with another indicator: the gasoline's anti-knock performance, also known as the octane rating or gasoline grade.
The differences in gasoline mainly lie in the octane rating and composition. For example, 92-octane gasoline has poorer anti-knock performance but is cheaper, making it suitable for low-compression engines. 95 and 98-octane fuels are better for high-compression vehicles, as their higher octane ratings reduce knocking and protect the engine. Cleaning performance also varies—higher-octane gasoline typically contains more detergent additives to minimize carbon deposits. I also pay attention to ethanol-blended gasoline, which contains 10% alcohol. While it's more environmentally friendly, it increases fuel consumption by 5%-10%. Gasoline quality varies significantly between stations, with some mixing in impurities, so it's best to choose reputable gas stations. Additionally, summer and winter gasoline formulations differ, with winter blends having better volatility to prevent cold-start difficulties.
