Diesel engines, which are also referred to as compression-ignition engines, are commonly used in various types of vehicles including trucks, tractors, and trains. However, there are various synonyms that are often used when referring to these engines. For instance, these engines are often referred to as oil engines, as they typically run on diesel fuel. Additionally, some people may refer to them as compression engines, as the ignition process relies on the compression of air within the cylinder. Other synonyms that might be used include diesel motor, diesel power plant, or diesel generator. Ultimately, regardless of the synonym used, diesel engines remain an essential component of modern transportation technologies.