How did the early gasoline engines in automobiles differ from modern engines in terms of design and efficiency?

Early gasoline engines were relatively simple and inefficient compared to modern engines. They often used low-compression cylinders and lacked many of the advancements in materials and technology seen today. Early engines also had limited power output, frequent mechanical issues, and were less fuel-efficient. Over time, advancements in technology and materials have greatly improved engine performance, efficiency, and reliability.