How much truck do I have/ it will pull?

[rmalikone]

Dear Knowledgeables,
I bought this truck last year without really knowing how much it could tow and how to calculate fifth wheel numbers. I do have the numbers from Ford's Towing guide. The wife and I, think we would like to go on the road in a few years (about 4) and figured it would best if we bought our truck now and have it paid off! I purchased a 2008 Ford 350 Lariat Crew Cab, 6.4 PSD Dual Wheel 4x4 w/ 4:30 rear axle ratio, w/ BW turn over ball hitch.
My reasons for this truck; used w/29,000 mi. (not excessive mileage) price was fair, liked that it's a Lariat, and a diesel - Engine should last for many miles considering that we won't be on the road for a couple of years. It should be able to pull/tow a pretty hefty 5'ver! I do know that it won't tow the biggest fifth wheels out there and thats OK.
So as the title asks - how to figure it out- Please give me the calculation formula as if I'm mentally challenged because I've seen a couple of ways to figure it out before and they don't make sense to me! (I am not totally ignorant about towing but do need EZ instructions. I've towed a TT before)
The 5'vers I'm looking at have these type of numbers - GVWR 15,000 lbs, unladen hitch wt. 2240 lbs. These are numbers from Keystone's Alpine - we like 3450RL AND 3500RE.
If for any reason u just want to give me it already figured out, that won't bother me, but I should know how to do it myself.

Thanks for any and all help!
Ron

[aspeyrer]

that should be plenty of truck to pull the fifth wheels you mention, but your not going to like the fuel mileage of that 6.4diesel, that twin turbo really drinks the diesel. there are some exhaust issues with the 6.4, and its regen cycles.

[RustyJC]

I would commend to your reading the following article by Ken Lenger, an iRV2 member. As you get to the bottom, Ken has provided a link to his Excel spreadsheet where you can enter the data to do your own calculations.

Rusty

[Cat320]

As somebody mentioned else where...actual tow capacity is the GCWR minus the weight of the truck when ready to tow.

[JeffinTD]

Also worth noting, listed empty weights for RV's are notoriously understated. Running it over a certified scale is the only real way to know what weight you are actually playing with.

Hitch weight will likely be about 20% of the loaded weight of the 5th wheel.

Anyway, I think you probably have enough truck for what you are looking at doing.