* Specific engine: The 6.4L Power Stroke V8 diesel was the only diesel option in 2009. However, even with the same engine, configurations differed.
* Axle ratio: Higher ratios allow for greater towing capacity.
* Cab configuration: Regular cab trucks generally have a higher towing capacity than crew cabs due to weight differences.
* Bed length: Shorter beds may slightly increase towing capacity.
* Options and added equipment: Additional weight from options reduces towing capacity.
Therefore, there's no single answer. To find the *exact* towing capacity for a *specific* 2009 Ford F-350 Super Duty Diesel Dually, you must consult the sticker located on the driver's side doorjamb, or the owner's manual for that particular truck. This sticker provides the GVWR (Gross Vehicle Weight Rating), GAWR (Gross Axle Weight Rating), and the specific towing capacity for that vehicle configuration.
However, a general range for a well-equipped 2009 F-350 Super Duty Dually with the 6.4L Power Stroke diesel would likely be in the 18,000 to 24,000 lb range for conventional towing. Fifth-wheel and gooseneck towing capacities will likely be even higher, but again, only the sticker and owner's manual can give you the precise number.
