What is the displacement of a 1.5L engine?
2 Answers
1.5L refers to the engine displacement of 1.5 liters, where 'L' denotes a naturally aspirated engine. Displacement is a crucial structural parameter that comprehensively measures the size of an engine. The performance indicators of an engine are closely related to its displacement, and unit displacement is often used as a basis for comparing the sizes of different engines. Displacement (Swept-volume) is a specialized term in hydraulic transmission, referring to the volume of fluid inhaled or expelled per stroke or cycle. The space volume through which the piston moves from the top dead center to the bottom dead center is called the cylinder displacement. If an engine has multiple cylinders, the sum of the working volumes of all cylinders is referred to as the engine displacement. Naturally aspirated (English: Naturally-Aspirated) is a type of car intake system where atmospheric pressure forces air into the combustion chamber without the use of any supercharger. Naturally aspirated engines far surpass turbocharged engines in terms of smooth power output and direct response. Apart from increasing displacement, another method to enhance the power of a naturally aspirated engine is to raise the compression ratio. However, too high a compression ratio can easily lead to knocking. To prevent knocking, higher-octane gasoline is required, which undoubtedly increases the owner's expenses. Automakers have employed various technologies to minimize knocking during the engine combustion process. For example, knock sensors installed on the cylinder block can detect knocking within the cylinder and send this signal to the Engine Management System (ECU). The computer then reacts to eliminate the knocking, such as retarding the ignition timing, but this can result in a reduction in power. Another method to reduce knocking is to lower the combustion chamber temperature by integrating more coolant passages in the cylinder head. Advantages of naturally aspirated engines: In terms of lifespan and maintenance costs, turbocharged engines do not last as long as naturally aspirated engines. The structure and maintenance of naturally aspirated engines are relatively simpler, offering greater advantages in smoothness, durability, stability, and safety compared to turbocharged engines. In terms of power, naturally aspirated engines provide smoother and more gradual acceleration, making them easier to control. They also produce lower noise levels.
As a veteran driver with ten years of experience, I often explain engine displacement to beginners. A 1.5L means the total gasoline volume all the cylinders can consume, equivalent to 1500 milliliters. My Japanese car has this displacement, averaging 7L/100km in city commuting and dropping to 6L on highways. The turbocharged version of the same model obviously has more punch during acceleration, but our naturally aspirated engine is cheaper to maintain—just over 200 yuan for an oil change. I chose this displacement mainly for balance: it won't struggle on hills like a 1.0L, nor burn hundreds more in monthly fuel costs like a 2.0L.
