Which of the following engines is typically used in commercial vehicles?

• A. Rotary Engine
• B. Turbine Engine
• C. Diesel Engine
• D. Steam Engine

Answer: (C)

The diesel engine is commonly employed in commercial vehicles due to its efficiency, durability, and capability of generating high torque at low speeds, which is essential for heavy loads. This type of engine operates on the diesel cycle, which allows for a higher compression ratio compared to gasoline engines, resulting in better fuel efficiency and power.

Additionally, diesel engines are well-suited for long distances and demanding driving conditions often encountered in commercial applications, such as trucks and buses. They tend to have a longer lifespan and require less maintenance than other engine types, making them not only cost-effective but also practical for businesses that rely on heavy-duty transportation.

In contrast, while turbine engines are often used in aviation, they are not practical for most ground vehicles due to their complexity and cost. Rotary engines, while innovative, have not gained widespread use in commercial vehicles for similar reasons. Steam engines, though historically significant, have largely been phased out in favor of more modern and efficient engine technologies.