Currently in their fifth generation, Super Duty trucks use a separate chassis from the F-150. The Super Duty's heavier-duty chassis components allows for heavier payloads and towing capabilities. With a GVWR over 8,500 lb (3,900 kg), Super Duty pickups are Class 2 and 3 trucks, while chassis-cab trucks are offered in Classes 3–6. The model line also offers Ford Power Stroke V8 diesel engines as an option.