What Materials Are Used in Car Engines?
2 Answers
Engine materials are generally divided into two types: cast iron engines and aluminum engines. Differences between cast iron engines and aluminum alloy engines: Cast iron engines: Cast iron engines exhibit minimal thermal deformation. For engines operating under prolonged high-temperature and high-pressure conditions, cast iron engines offer excellent heat resistance and are less prone to deformation. Additionally, cast iron engines are easier and cheaper to repair when worn out, and they are more convenient to manufacture compared to aluminum alloy engines. However, they are heavier and have inferior heat dissipation compared to aluminum engines. Aluminum alloy engines: Compared to cast iron engines, aluminum alloy engines are lighter and dissipate heat faster, aligning with the current focus on environmental protection and fuel efficiency. The lightweight nature of aluminum alloy engines effectively reduces the engine's own weight, contributing to relatively better fuel economy. Faster heat dissipation plays a crucial role in protecting the engine, which is why most passenger car engines now use aluminum alloy engines. However, compared to cast iron engines, aluminum engines are more prone to deformation under heat, have higher maintenance costs, and more complex repair procedures.
I've driven quite a few older cars, mostly from the 80s and 90s, where the engine blocks were mostly made of cast iron. That stuff was heavy and durable, but the heat dissipation wasn't great—after driving for a while, the engine bay would get as hot as an oven. New cars these days are different; mainstream engine blocks are mostly made of aluminum alloy, which is much lighter, making the car more responsive and fuel-efficient, especially noticeable in city traffic jams. The cylinder heads are also mostly aluminum, offering better heat dissipation and the ability to handle long-distance driving without overheating. However, cast iron is still common in some trucks or off-road vehicles—it's tough and can take a beating, but the weight affects acceleration, and fuel consumption goes up when the tank is full. Overall, material advancements have made cars run more smoothly, with fuel consumption dropping from over 10 liters per 100 km to around 6-7 liters. Maintenance is also easier—older cars needed frequent rust checks, while newer cars with aluminum alloy engines are simpler to maintain, though you have to watch out for acid and alkali corrosion. This knowledge comes from years of driving experience. When choosing a car, it depends on whether you prioritize durability or efficiency.
