SHAME ON YOU GUYS! You've hijacked Lynne's important towing question and turned it into a computer discussion!

Lynne,

You need to locate the GCWR - it is one of three critical numbers. GCWR is Gross Combined Weight Rating and is the maximum weight of truck & trailer combined when fully loaded for the road. The other two are the Actual Vehicle Weight (measured or calculated) and the GVWR, which you have (10,000 lbs). You need to determine the actual weight of your truck, preferably by weighing it at a public scale but you can estimate it from the manufacturer's spec for unladen vehicle weight. That will enable you to determine how muchweight carrying capacity is left, called *payload*.

Here's the Ford truck spec page for 2006, but your 2005 should be the same: http://www.fordvehicles.com/trucks/superduty/features/specs/

It shows a max payload of 2600 lbs for a Superduty Crewcab diesel. The Payload in the chart is Ford's *estimate* of the difference between the trucks unloaded (empty) weight and the GVWR. Their estimate includes a 150 lb driver and fuel but not any gear onboard, e.g. a fifth wheel hitch, maybe a passenger or pet, recreational gear, etc. Figure at least another 150 lbs for the hitch plus whatever else you may carry with you. That further reduces your available payload to something under 2450 lbs. That would be the maximum hitch (kingpin) weight of the fifth wheel you could tow. In practice it will be less because ALL the fifth wheel weight falls on the rear axle, which cannot by itself carry the entire Payload. Again, the only way to find out for sure what can be carried on the back is to weigh the rear axle empty and subtract that from the rear GAWR (6100 lbs), but I'm going to guess it will be about 2200 lbs.

The Ford fifth wheel towing capacity *estimate* shows a max of 15,500 lbs for an F250 diesel automatic with 3.73 rear axle, but you have to subtract any weight you added to the truck yourself. Again, that's the hitch and any gear & passengers onboard. I used a 150 lb estimate for the hitch above, so subtract 150 plus anything you may carry with you. Maybe estimate 300 lbs for now. Later when you weigh the truck we can calculate it more accurately. That estimate is a bit higher than is typical for this truck, but close enough for now.

So, all this says you could tow a 15,200 lb trailer that has a kingpin (hitch) weight of about 2200 lbs. Any 15,000 lb trailer is probably going to have more than 2200 lbs on the hitch when loaded, so you are probably looking at something in the range of 14,000 lbs tops. [I estimated that a 15,000 lb trailer with 15% of its weight on the hitch would put a 2250 lb load on the hitch. 15% is fairly ight for a loaded fifth wheel, but there is a lot of variation among them.]

I've done some scientific wild-assed guessing [SWAG] here, based on the Ford estimates and experience. Actually weighing things is the right way to do it, but this should give you an idea of what you can shop for. Once you find something you like we can see if more accurate data is needed. You might choose something enough under the maximums so that you don't have to worry.