Which type of CNG container is used exclusively to propel the vehicle?

The type of CNG container that is used exclusively to propel the vehicle is the motor fuel container. This container is specifically designed to store compressed natural gas that powers the engine of a vehicle, making it a critical component in vehicles that run on natural gas. These containers are engineered to meet strict safety standards and pressure requirements, ensuring that the fuel remains secure and efficient for vehicle operation.

In contrast, auxiliary fuel containers are utilized to provide additional fuel beyond the primary source but are not solely dedicated to propulsion. Mobile fuel containers might refer to flexible, transportable units that can store and transport CNG but are not specifically designed for vehicle propulsion. Portable containers are generally for temporary or emergency use and may not meet the same specifications required for supplying fuel directly to a vehicle's engine. Therefore, the motor fuel container stands out as the definitive option directly associated with the propulsion of the vehicle.