From the 2014 F-150 Manual
Payload - is the combined weight
of cargo and passengers that the
vehicle is carrying. The maximum
payload for your vehicle can be
found on the Tire Label on the
B-Pillar or the edge of the driver
door (vehicles exported outside
the US and Canada may not have
a Tire Label). Look for “THE
COMBINED WEIGHT OF
OCCUPANTS AND CARGO
SHOULD NEVER EXCEED XXX
kg OR XXX lb.” for maximum
payload. The payload listed on the
Tire Label is the maximum
payload for the vehicle as built by
the assembly plant. If you install
any aftermarket or
authorized-dealer installed
equipment on the vehicle, you
must subtract the weight of the
equipment from the payload listed
on the Tire Label in order to
determine the new payload.
It mentions that tounge wt. is also included on the next page.