General Motors' new Chevrolet Silverado medium-duty trucks are not variants of existing models, the automaker says. The trucks were built from the ground up to cater to the needs of fleet and commercial buyers. They can be fitted with work-specific beds and boxes for work such as landscaping, emergency services, refrigeration and towing. Medium-duty trucks range from Class 4 through Class 6, based on gross vehicle weight ratings, which is the maximum operating weight/mass of a vehicle. The new Silverado has a maximum weight of 22,500 pounds, which reaches into the middle of the Class 6 trucks.