An "inline-four" engine is a type of internal combustion engine that features four cylinders arranged in a straight line. This configuration is popular in many vehicles due to its compact size, lightweight design, and efficient performance. Inline-four engines are commonly found in small to mid-sized cars, providing a good balance of power and fuel efficiency. The inline-four design allows for smoother operation and simpler manufacturing compared to other engine types, such as V6 or V8 engines. Many modern vehicles utilize turbocharging with inline-four engines to enhance power output while maintaining fuel economy, making them a versatile choice for various automotive applications.