Ford F-150 2010 Owner's Manual page 254

Tires, Wheels and Loading
GCW (Gross Combined Weight) – is the weight of the loaded vehicle
(GVW) plus the weight of the fully loaded trailer.
GCWR (Gross Combined Weight Rating) – is the maximum allowable
weight of the vehicle and the loaded trailer – including all cargo and
passengers – that the vehicle can handle without risking damage.
(Important: The towing vehicle's braking system is rated for operation at
GVWR, not at GCWR.) Separate functional brakes should be used for
safe control of towed vehicles and for trailers where the GCW of the
towing vehicle plus the trailer exceed the GVWR of the towing vehicle.
The GCW must never exceed the GCWR.
Maximum Loaded Trailer Weight – is the highest possible weight of a
fully loaded trailer the vehicle can tow. It assumes a vehicle with only
mandatory options, no cargo (internal or external), a tongue load of
10–15% (conventional trailer) or king pin weight of 15–25% (fifth wheel
trailer), and driver only (150 lb. [68 kg]). Consult your authorized
dealer (or the RV and Trailer Towing Guide provided by your
authorized dealer) for more detailed information.
Tongue Load or Fifth Wheel King Pin Weight – refers to the amount
of the weight that a trailer pushes down on a trailer hitch.
Examples: For a 5,000 lb. (2,268 kg) conventional trailer, multiply 5,000
by 0.10 and 0.15 to obtain a proper tongue load range of 500 to 750 lb.
(227 to 340 kg). For an 11,500 lb. (5,216 kg) fifth wheel trailer, multiply
by 0.15 and 0.25 to obtain a proper king pin load range of 1,725 to
2,875 lb. (782 to 1,304 kg)
WARNING: Do not exceed the GVWR or the GAWR specified on
the Safety Compliance Certification Label.
WARNING: Do not use replacement tires with lower load
carrying capacities than the original tires because they may
lower the vehicle's GVWR and GAWR limitations. Replacement tires
with a higher limit than the original tires do not increase the GVWR
and GAWR limitations.
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