2021 FORD F-150 tire size

sand, steep slopes, or pulling heavy
objects. Additionally, the system is capable
of recreational flat towing by putting the
transfer case into neutral (N). See
Recreationally Towing Your Vehicle
(page
490).
There is further information on driving in
unique driving conditions.
See Off-Road
Driving (page 470).
FOUR-WHEEL DRIVE
PRECAUTIONS WARNING:
Vehicles with a higher
center of gravity (utility and four-wheel
drive vehicles) handle differently than
vehicles with a lower center of gravity
(passenger cars). Avoid sharp turns,
excessive speed and abrupt steering in
these vehicles. Failure to drive cautiously
increases the risk of losing control of your
vehicle, vehicle rollover, personal injury
and death. WARNING:
Do not become
overconfident in the ability of four-wheel
drive vehicles. Although a four-wheel
drive vehicle may accelerate better than
a two-wheel drive vehicle in low traction
situations, it won't stop any faster than
two-wheel drive vehicles. Always drive
at a safe speed.
Truck and utility vehicles can differ from
some other vehicles. Your vehicle could be
higher to allow it to travel over rough
terrain without getting stuck or damaging
underbody components. The differences
that make your vehicle so versatile also
make it handle differently than an ordinary
passenger car. Always maintain steering
wheel control, especially in rough terrain.
Since sudden changes in terrain can result
in abrupt steering wheel motion, make sure
you grip the steering wheel from the outside. Do not grip the spokes. Drive
cautiously to avoid vehicle damage from
concealed objects such as rocks and
stumps. Drive slower in strong crosswinds
which can affect the normal steering
characteristics of your vehicle. Be
extremely careful when driving on
pavement made slippery by loose sand,
water, gravel, snow or ice.
Note:
Do not use four-wheel drive high or
four-wheel drive low mode on dry, hard
surfaced roads. Doing so can produce
excessive noise, increase tire wear and can
damage drive components.
FOUR-WHEEL DRIVE
LIMITATIONS
Operating Four-Wheel Drive with
a Spare or Mismatched Tires
(If
Equipped)
On four-wheel drive vehicles, the size of
the spare tire can affect the four-wheel
drive system. If there is a significant
difference between the size of the spare
tire and the remaining tires, you could have
limited four-wheel drive functionality.
When driving with the full-size dissimilar
spare wheel and tire assembly, we
recommend that you do not:
• Exceed
50 mph (80 km/h) with a
four-wheel drive mode turned on.
• Turn on a four-wheel drive mode
unless the vehicle is stationary.
• Use a four-wheel drive mode on dry
pavement.
Driving with the full-size dissimilar spare
wheel and tire assembly can limit
four-wheel drive functionality, especially
when driving in a mechanically locked
four-wheel drive mode. You can experience
the following:
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(If Equipped)

•
Additional noise from the transfer case
or other drive components.
• Difficulty shifting out of a mechanically
locked four-wheel drive mode.
Use of a dissimilar spare wheel and tire
assembly can lead to impairment of the
following:
• Comfort and noise.
• Winter weather driving capability.
• Wet driving capability.
• Four-wheel drive capability.
Mechanical Shift Blocking
On four-wheel drive vehicles with a
mechanically locked four-wheel drive high
mode, the transfer case distributes torque
to the front wheels by mechanically
interlocking the front and rear driveshafts
together. Various external factors can
affect shifting performance of this type of
system including, but not limited to:
• Vehicle acceleration.
• Dissimilar tire sizes.
• Steering input.
If the system detects a mechanical shift
blockage at speed after you select
two-wheel drive high, the message "4x4
Unable to Disengage See Manual", could
display momentarily. If this message
displays, one or more of the following
actions can relieve the mechanical shift
block:
• Momentary acceleration.
• Momentary braking.
• Bringing the vehicle to a stop.
• Shifting the transmission to neutral and
back to drive.
• Shifting the transmission to reverse
and back to drive.
• Driving the vehicle around a tight turn
at a slow speed. SELECTING A FOUR-WHEEL
DRIVE MODE - RAPTOR
The four-wheel drive mode control is on
the instrument panel.
To select a four-wheel drive mode, press
the four-wheel drive mode control button
of the desired mode. You can select
two-wheel drive high (2H), four-wheel
drive high (4H), or four-wheel drive auto
(4A) at a stop or while driving. Once the
shift is complete, the information display
will then display the selected four-wheel
drive mode. While shifts are in progress,
the lights on the four-wheel drive control
switch can flash and you could see
messages in the information display
indicating that a shift is in progress or to
release the accelerator pedal to improve
shift performance.
Note:
Do not perform this operation if the
rear wheels are slipping or while applying
the accelerator pedal.
Note: You could hear some noise as the
system shifts or engages, which is normal.
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WHAT IS THE ELECTRONIC
LOCKING DIFFERENTIAL
The electronic locking differential is a
device housed in the rear axle, and can
provide additional traction when needed.
HOW DOES THE ELECTRONIC
LOCKING DIFFERENTIAL
WORK - RAPTOR
You can activate the differential
electronically and shift it on the fly within
the operating speed range. The electronic
differential disengages when the vehicle
speed exceeds a set value and it reengages
when the vehicle speed goes below a set
value depending on drive mode. See
Switching the Electronic Locking
Differential On and Off (page 303). The
electronic locking differential is for use in
mud, rocks, sand, or any off-road condition
where you need maximum traction.
Note:
The electronic locking differential can
activate or deactivate automatically based
on speed, four-wheel drive mode, and drive
mode selection. See Switching the
Electronic Locking Differential On and
Off
(page 303).
Note: The electronic locking differential is
for off-road use only and is not for use on
dry pavement. Using the electronic locking
differential on dry pavement results in
increased tire wear, noise and vibration.
Note: The electronic locking differential is
not available in 2H. HOW DOES THE ELECTRONIC
LOCKING DIFFERENTIAL
WORK
You can activate the differential
electronically and shift it on the fly within
the operating speed range. The electronic
differential disengages when the vehicle
speed exceeds a set value, and reengages
when the vehicle speed goes below a set
value. See
Switching the Electronic
Locking Differential On and Off (page
303). It also engages based on certain
selected drive modes. See Selecting a
Drive Mode (page 373). The electronic
locking differential is for use in mud, rocks,
sand, or any off-road condition where you
need maximum traction.
Note: The electronic locking differential can
activate or deactivate automatically based
on speed, four-wheel drive mode, and drive
mode selection.
See Switching the
Electronic Locking Differential On and
Off
(page 303).
Note: The electronic locking differential is
for off-road use only and is not for use on
dry pavement. Using the electronic locking
differential on dry pavement results in
increased tire wear, noise and vibration.
ELECTRONIC LOCKING
DIFFERENTIAL PRECAUTIONS
Operating the Electronic Locking
Differential with a Spare or
Mismatched Tires
On vehicles with an electronic locking
differential, the size of the spare tire can
affect performance of the system. If there
is a significant difference between the two
rear tires, you may have limited electronic
locking differential functionality. If the
system has difficulty disengaging, release
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(If Equipped)

HOW DOES STABILITY
CONTROL WORK
WARNING: Vehicle modifications
involving braking system, aftermarket
roof racks, suspension, steering system,
tire construction and wheel and tire size
may change the handling characteristics
of your vehicle and may adversely affect
the performance of the electronic
stability control system. In addition,
installing any stereo speakers may
interfere with and adversely affect the
electronic stability control system.
Reducing the effectiveness of the
electronic stability control system could
lead to an increased risk of loss of vehicle
control, vehicle rollover, personal injury
and death. WARNING:
Remember that even
advanced technology cannot defy the
laws of physics. It's always possible to
lose control of a vehicle due to
inappropriate driver input for the
conditions. Aggressive driving on any
road condition can cause you to lose
control of your vehicle increasing the risk
of personal injury or property damage.
Activation of the electronic stability
control system is an indication that at
least some of the tires have exceeded
their ability to grip the road; this could
reduce the operator's ability to control
the vehicle potentially resulting in a loss
of vehicle control, vehicle rollover,
personal injury and death. WARNING: You are responsible for
controlling your vehicle at all times. The
system is designed to be an aid and does
not relieve you of your responsibility to
drive with due care and attention. Failure
to follow this instruction could result in
the loss of control of your vehicle,
personal injury or death.
If a driving condition activates either the
stability control or traction control you may
experience the following conditions:
• The stability and traction control light
flashes.
• Your vehicle slows down.
• Reduced engine power.
The stability control system has several
features built into it to help you maintain
control of your vehicle:
Electronic Stability Control
Electronic stability control enhances your
vehicle ’s ability to prevent skids or lateral
slides by applying brakes to one or more
of the wheels individually and, if necessary,
reducing engine power.
Roll Stability Control
Roll stability control enhances your
vehicle ’s ability to prevent rollovers by
detecting your vehicle ’s roll motion and
the rate at which it changes by applying
the brakes to one or more wheels
individually.
Curve Control
Curve control enhances your vehicle ’s
ability to follow the road when cornering
severely or avoiding objects in the roadway.
Curve control operates by reducing engine
power and, if necessary, applying brakes
to one or more of the wheels individually.
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Why does active park assist not offer
a parking space?
There is not enough room in the
parking space for your vehicle to safely
park.
Why does active park assist not offer
a parking space? There is not enough space for the
parking maneuver on the opposite side
of the parking space.
Why does active park assist not offer
a parking space? The parking space is more than 5 ft
(1.5 m) or less than 2 ft (0.5 m) away
from your vehicle.
Why does active park assist not offer
a parking space? Your vehicle's speed is greater than
22 mph (35 km/h) for parallel parking
or greater than
19 mph (30 km/h) for
perpendicular parking.
Why does active park assist not offer
a parking space? You recently disconnected or replaced
the battery. After you reconnect the
battery you must drive your vehicle on
a straight road for a short period of
time.
Why does active park assist not
correctly position the vehicle into a
parking space? An irregular curb along the parking
space prevents the system from
correctly aligning your vehicle.
Why does active park assist not
correctly position the vehicle into a
parking space? Vehicles or objects bordering the
space could not be correctly parked. Why does active park assist not
correctly position the vehicle into a
parking space?
Your vehicle stopped too far past the
parking space.
Why does active park assist not
correctly position the vehicle into a
parking space? The tires are not correctly installed or
maintained. For example, using a spare
tire, not inflated correctly, improper
size, or of different sizes.
Why does active park assist not
correctly position the vehicle into a
parking space? A repair or alteration changed the
detection capabilities.
Why does active park assist not
correctly position the vehicle into a
parking space? A parked vehicle has a high
attachment. For example, a salt
sprayer, snowplow or moving truck
bed.
Why does active park assist not
correctly position the vehicle into a
parking space? The parking space length, or position
of parked objects, changes after your
vehicle passes the space.
Why does active park assist not
correctly position the vehicle into a
parking space? The temperature around your vehicle
quickly changes. For example, driving
from a heated garage into a cold
outside temperature, or after leaving
a car wash.
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F-150 (TFD) Canada/United States of America, enUSA, Edition date: 202104, Second-Printing Active Park Assist
(If Equipped)

HOW DOES ADAPTIVE CRUISE
CONTROL WITH STOP AND GO
WORK
Adaptive cruise control with stop and go
uses radar and camera sensors to maintain
a set gap between your vehicle and the
vehicle in front of you while following it to
a complete stop. Stop and go can also be
set to follow a vehicle directly in front of
you and adjust the set speed, while you are
at a complete stop.
ADAPTIVE CRUISE CONTROL
PRECAUTIONS
WARNING: You are responsible for
controlling your vehicle at all times. The
system is designed to be an aid and does
not relieve you of your responsibility to
drive with due care and attention. Failure
to follow this instruction could result in
the loss of control of your vehicle,
personal injury or death. WARNING: Do not use adaptive
cruise control on winding roads, in heavy
traffic or when the road surface is
slippery. This could result in loss of
vehicle control, serious injury or death. WARNING:
Pay close attention to
changing road conditions such as
entering or leaving a highway, on roads
with intersections or roundabouts, roads
without visible lanes of travel, roads that
are unpaved, or steep slopes. Failure to
follow this instruction could result in the
loss of control of your vehicle, personal
injury or death. WARNING:
The system is not a
crash warning or avoidance system. WARNING:
Do not use the system
when towing a trailer that has
aftermarket electronic trailer brake
controls. Failure to follow this instruction
could result in the loss of control of your
vehicle, personal injury or death. WARNING:
Do not use tire sizes
other than those recommended because
this can affect the normal operation of
the system. Failure to do so may result
in a loss of vehicle control, which could
result in serious injury. WARNING:
Do not use the system
with a snow plow blade installed. WARNING:
Do not use the system
in poor visibility, for example fog, heavy
rain, spray or snow.
When Following a Vehicle WARNING:
When following a
vehicle that is braking, your vehicle does
not always decelerate quickly enough to
avoid a crash without driver intervention.
Apply the brakes when necessary. Failure
to follow this instruction could result in
personal injury or death.
Hilly Condition Usage
Select a lower gear when the system is
active in situations such as prolonged
downhill driving on steep slopes, for
example in mountainous areas.
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F-150 (TFD) Canada/United States of America, enUSA, Edition date: 202104, Second-Printing Adaptive Cruise Control
(If Equipped)

WHAT IS TRAILER HITCHING
ASSISTANCE
Trailer hitching assistance helps the driver
align the vehicle hitch ball to a trailer
coupler.
HOW DOES TRAILER HITCHING
ASSISTANCE WORK
Trailer hitching assistance uses the
following to detect your trailer:
•
Rear view camera.
• Radar.
• Parking aid sensors.
• External rear lighting.
This feature also controls the following to
align the hitch ball with the trailer coupler:
• Steering.
• Shifting.
• Braking and acceleration.
Note: Blocked sensors could affect system
performance. Do not cover the sensors with
bumper stickers, tape, repair compound or
other objects.
TRAILER HITCHING
ASSISTANCE PRECAUTIONS WARNING: You are responsible for
controlling your vehicle at all times. The
system is designed to be an aid and does
not relieve you of your responsibility to
drive with due care and attention. Failure
to follow this instruction could result in
the loss of control of your vehicle,
personal injury or death. WARNING: The system is not
designed to detect cyclists,
motorcyclists, pedestrians or animals.
Apply the brakes when necessary. Failure
to follow this instruction could result
personal injury or death. WARNING:
The system may not
operate properly during severe weather
conditions, for example snow, ice, heavy
rain and spray. Always drive with due
care and attention. Failure to take care
may result in a crash.
Note: Trailer hitching assistance only works
with conventional trailers, couplers and
hitch balls.
Note: The hitch ball must be properly
installed on the vehicle for the system to
function as intended. An improperly
installed hitch ball could result in damage
to your vehicle or trailer.
Note: Certain aftermarket modifications
such as oversized tires or lift kits could make
trailer hitching assistance fail or not work
as intended.
Note: Keep the sensors and camera free
from snow, ice and dirt.
Note: Clean the camera lens with a soft,
lint-free cloth and non-abrasive cleaner.
TRAILER HITCHING
ASSISTANCE LIMITATIONS
The system could not function or could
function with reduced performance during
the following:
• When using trailer hitching assistance
in tall grass and weeds.
• When safety chains, cables or wiring
are dangling near the coupler.
• When using trailer hitching assistance
on slippery surfaces.
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•
Moderate braking is particularly
important since it allows you to
maximize the energy captured by the
regenerative braking system.
• Drive at steady speeds without
stopping.
• Anticipate stops; slowing down may
eliminate the need to stop.
• Driving on flat terrain.
• Drive at reasonable speeds and
observe posted speed limits.
• Shut all windows when driving at high
speeds.
• Combine errands and minimize
stop-and-go driving.
• Drive with the tonneau cover installed
if your vehicle comes with one.
• Keep the tires properly inflated and use
only the recommended size.
• Use the recommended engine oil.
• Follow the recommended maintenance
schedule and carry out the
recommended checks.
• Perform all scheduled maintenance.
Note: Having your engine running is not
always an indication of inefficiency. In some
cases, it is actually more efficient than
driving in electric mode.
Avoid these actions; they reduce your fuel
consumption:
• Revving the engine.
• Aggressive driving increases the
amount of energy required to move
your vehicle.
• Driving in lower temperatures during
the first 5–10 mi (12 –16 km) of driving.
• Idle for periods longer than one minute.
• Use the air conditioner or front
defroster. •
Adding certain accessories to your
vehicle like bug deflectors, rollbars,
light bars, running boards, ski racks or
luggage racks.
• Use the speed control in hilly terrain.
• Using fuel blended with alcohol.
• Drive a heavily loaded vehicle or tow a
trailer.
• Driving with the wheels out of
alignment.
DRIVING IN SPECIAL
CONDITIONS
EMERGENCY MANEUVERS
In an unavoidable emergency where you
must make a sudden sharp maneuver, turn
the steering wheel only as rapidly and as
far as required to avoid the emergency.
Apply smooth pressure to the accelerator
pedal or brake pedal as needed. Avoid
abrupt steering, acceleration and braking
changes. Abrupt changes could increase
the risk of vehicle roll over, loss of vehicle
control and personal injury. If possible, use
any available road surfaces to bring your
vehicle under control.
FLOOR MATS WARNING:
Use a floor mat
designed to fit the footwell of your
vehicle that does not obstruct the pedal
area. Failure to follow this instruction
could result in the loss of control of your
vehicle, personal injury or death. WARNING:
Pedals that cannot
move freely can cause loss of vehicle
control and increase the risk of serious
personal injury.
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F-150 (TFD) Canada/United States of America, enUSA, Edition date: 202104, Second-Printing Driving Hints