What are 95 and 98 gasoline?
2 Answers
95 and 98 are both octane ratings for gasoline. 95-octane gasoline is composed of 95% isooctane and 3% n-heptane. When the engine compression ratio is high, high-octane gasoline should be used. If low-octane gasoline is used with a high compression ratio, it can cause abnormal combustion, resulting in knocking, increased fuel consumption, and reduced driving power. 98-octane gasoline refers to gasoline with an octane rating equal to a mixture of 98% isooctane and a certain percentage of n-heptane. 98-octane gasoline has better anti-knock properties and higher power output, while also producing fewer harmful substances and lower exhaust emissions. Different octane ratings indicate different levels of octane values, with higher-rated gasoline having higher octane values and better stability. The differences in gasoline octane ratings: The higher the octane rating, the better the anti-knock performance. Anti-knock performance refers to the gasoline's ability to resist knocking during engine combustion. When refueling, different gasoline grades should be selected based on the engine's compression ratio (the ratio of the cylinder's maximum volume at bottom dead center to its minimum volume at top dead center). Long-term effects of using the wrong gasoline octane rating: Using a higher octane gasoline in a vehicle designed for lower octane will not cause damage, but the increased octane value can alter the fuel's ignition point, leading to delayed combustion in the engine. This reduces the engine's power output and thermal efficiency. Conversely, using lower octane gasoline in a high-octane vehicle can cause engine knocking, increased resistance during the upward stroke, and abnormal wear on pistons and cylinders, potentially leading to severe engine damage. Refueling precautions: When refueling: Turn off the engine, avoid making phone calls or using mobile devices, and do not use open flames in the gas station. Always turn off the engine while refueling. If there is a queue, wait in line orderly without cutting in. Selecting gasoline: Always choose reputable gas stations with high-quality fuel. Avoid gas stations with poor-quality gasoline. Long-term use of low-quality gasoline can lead to increased carbon deposits in the engine. It's essential to select both a reputable gas station and the correct gasoline octane rating. Choosing the right gasoline octane rating is crucial. Most vehicles have the manufacturer's recommended gasoline octane rating printed inside the fuel filler cap. Follow this recommendation when refueling. If the label states: "Use 92 or higher octane gasoline," then either 92 or 95 octane can be used, but they should not be mixed. If the label states: "Use no less than 95 octane gasoline," then only 95 or 98 octane gasoline should be used, and 92 octane must be avoided. Higher octane gasoline is not always better; the engine's compression ratio must match the gasoline octane rating. Using higher octane gasoline in a low-compression engine may reduce knocking but can alter the ignition timing, leading to increased carbon deposits in the cylinders. Long-term use can negatively impact the engine's lifespan. Using lower octane gasoline in a high-compression engine can cause knocking, accelerating wear and tear on engine components.
95 and 98 octane refer to the grades of gasoline, where the numbers represent the octane rating, simply put, the fuel's ability to resist knocking. Knocking sounds scary, but it's actually the noise and damage caused by the premature ignition of the air-fuel mixture in the engine. Having driven many cars, I've found that regular family cars like my old Toyota only require 95 octane as recommended in the manual, which is cost-effective. However, high-performance cars like my friend's sports car must use 98 octane; otherwise, the engine may shudder and develop problems. Choosing fuel isn't just about price; the key is to check the vehicle's manual. Using lower octane fuel indiscriminately can cause the engine to retire early and increase repair costs. Gas stations usually clearly label 95 and 98 octane. I recommend regularly checking fuel quality when refueling to ensure the engine runs smoothly.
