bexiga

I called Ford today to find out excactly how much the tow rating on my truck, based on my Vin # ford states my truck is rated at 10,200lbs max tow.

ragerjr

bexiga, What does the yellow sticker say that your max cargo and passengers can be?

130428

that's all good and well on paper, but as asked, the payload # for your particular truck is more often than not your limiting number.
Plenty of knowledge in this towing section

smokeywren

Tow rating is GCWR minus the weight of the truck. GCWR depends on the power and torque of your drivetrain at the rear wheels. So GCWR is changed if you change either the rear axle ratio or the rolling radius of your tires (tire revs/mile).


Example: Tire diameter in inches is not accurate enough, so the industry uses tire revolutions per mile.


P275/65R18 = 652 revs/mile
P275/70R18 = 630 revs/mile
LT275/65R20 = 609 revs/mile


It requires more drivetrain power and torque to turn those tires fewer times to cover the same distance. That's called leverage.


The percentage difference in the revs/mile will tell you the percentage difference in your speedometer and in your actual rear axle ratio. That change in actual rear axle ratio is what reduces your GCWR (and tow rating).


So if you replace your stock P275/65R18 tires with taller aftermarket P275/70R18, then 652 minus 630 = 22, divided by 652 = 3.4%. So your speedometer will be slow by 3.4%, and your 3.55 axle ratio will "feel like" a 3.43.


If you replace your 18" tires and wheels with LT275/65R20 tires and matching wheels, then 652 minus 609 = 43, divided by 652 = 6.6%. So your speedo will be slow by 6.6%, or an indicated 70 MPH will be an actual 74.62 MPH on Officer Bob's Gotcha machine. And your 3.55 ratio will feel like it's a 3.31 when dragging a heavy trailer.

PerryB

F150 with a 5.5' bed is about the least suitable candidate for a 5th wheel I can think of. Sorry for being so blunt, but you should figure out how much trailer you want and pick the tow vehicle accordingly.

SkiSmuggs

Actually, a Chevy or Dodge 1500 would be worse. My F150 SB had an 1850 lb payload and a Sidewinder pinbox with no issues in 3 seasons including the mountains out west. But I had Max Tow, got the XLT for reduced weight and would have gotten the HD payload package had it been available for 2011. You have to plan for it; it can't just be an after thought. I went with the F150 because of long commutes on country roads, but bought it knowing I would be getting a fifth wheel. Then there were the discussions with the wife wanting something too heavy and me having to say no. A Super Duty is an easier solution.
My F150 with SuperSprings and Bilstein HD shocks felt just as solid on the road as my F350 does, but I don't have to worry about loading and can use the bed of the F350.

PerryB

I was thinking within the Ford family but you are correct. In this case I think the 5.5' bed is the major issue. I guess a Superglide mounted as far back as possible (safely) might work but then there goes more payload, because its a heavy hitch. Also I haven't seen much in the way of smaller 5th wheel trailers in recent years. Years ago my wife and I had a little 23' 5th that we pulled with our 1/2 tons, an F150 and a 1500 Chevy. We loved that trailer but when kid #2 came along it was time for a bigger trailer and truck. After a couple interim upgrades we are now hauling a 37' Montana with a 350/6.7. One son is almost out of the house and the other is two years behind so we are starting to look for our next - somewhat smaller - trailer.