tire size INFINITI QX50 2021 User Guide

WARNING
• Do not drive beyond the performance ca-
pability of the tires. Accelerating quickly,
sharp steering maneuvers or sudden
braking may cause loss of control, even
with Intelligent AWD engaged.
• For AWD equipped vehicles, do not at-
tempt to raise two wheels off the ground
and shift the transmission to any drive or
reverse position with the engine running.
Doing so may result in drivetrain damage
or unexpected vehicle movement which
could result in serious personal injury or
vehicle damage.
• Do not attempt to test an AWD
equipped vehicle on a 2-wheel dyna-
mometer (such as the dynamometers
used by some states for emissions test-
ing) or similar equipment even if the
other two wheels are raised off the
ground. Make sure that you inform the
test facility personnel that your vehicle is
equipped with AWD before it is placed
on a dynamometer. Using the wrong test
equipment may result in drivetrain dam-
age or unexpected vehicle movement
which could result in serious personal in-
jury or vehicle damage.CAUTION
• Do not operate the engine on a free roller
when any of the wheels are raised.
• If you use the free roller, rotate four
wheels with the same speed without
raising any wheels.
• If an AWD warning message is displayed
while driving there may be a malfunction
in the AWD system. Reduce the vehicle
speed immediately and have your vehicle
checked as soon as possible. It is recom-
mended that you visit an INFINITI re-
tailer for this service.
• The powertrain may be damaged if you
continue driving when the AWD tem-
perature or tire size incorrect messages
are displayed.
• If the AWD high temperature message is
displayed while you are driving, pull off
the road in a safe area, and idle the en-
gine. The driving mode will change to
2WD to prevent the AWD system from
malfunctioning. If the warning message
turns off, you can drive again. •
If the tire size incorrect message is dis-
played while you are driving, pull off the
road in a safe area with the engine idling.
Check that all tire sizes are the same,
that the tire pressure is correct and that
the tires are not excessively worn.
• If a warning message continues to be dis-
played after the above operations, have
your vehicle checked as soon as possible.
It is recommended that you visit an
INFINITI retailer for this service.
Starting and driving5-147

The brake system has two separate hydraulic
circuits. If one circuit malfunctions, you will
still have braking at two wheels.
BRAKE PRECAUTIONS
Vacuum assisted brakes
The brake booster aids braking by using en-
gine vacuum. If the engine stops, you can
stop the vehicle by depressing the brake
pedal. However, greater foot pressure on the
brake pedal will be required to stop the ve-
hicle and stopping distance will be longer.
Using the brakes
Avoid resting your foot on the brake pedal
while driving. This will overheat the brakes,
wear out the brake pads faster, and reduce
gas mileage.
To help reduce brake wear and to prevent the
brakes from overheating, reduce speed and
downshift to a lower gear before going down
a slope or long grade. Overheated brakes
may reduce braking performance and could
result in loss of vehicle control.
WARNING
• While driving on a slippery surface, be
careful when braking, accelerating or
downshifting. Abrupt braking or accel-
erating could cause the wheels to skid
and result in an accident.
• If the engine is not running or is turned
off while driving, the power assist for the
brakes will not work. Braking will be
harder.
Wet brakes
When the vehicle is washed or driven through
water, the brakes may get wet. As a result,
your braking distance will be longer and the
vehicle may pull to one side during braking.
To dry the brakes, drive the vehicle at a safe
speed while lightly pressing the brake pedal to
heat up the brakes. Do this until the brakes
return to normal. Avoid driving the vehicle at
high speeds until the brakes function correctly.
Parking brake break-in
Break in the parking brake shoes whenever
the stopping effect of the parking brake is
weakened or whenever the parking brake
shoes and/or rotors are replaced, in order to
assure the best brake performance. This procedure is described in the INFINITI
Service Manual. It is recommended that you
visit an INFINITI retailer for this service.
ANTI-LOCK BRAKING SYSTEM
(ABS)
WARNING
• The ABS is a sophisticated device, but it
cannot prevent accidents resulting from
careless or dangerous driving tech-
niques. It can help maintain vehicle con-
trol during braking on slippery surfaces.
Remember that stopping distances on
slippery surfaces will be longer than on
normal surfaces even with ABS. Stop-
ping distances may also be longer on
rough, gravel or snow covered roads, or
if you are using tire chains. Always main-
tain a safe distance from the vehicle in
front of you. Ultimately, the driver is re-
sponsible for safety.
• Tire type and condition may also affect
braking effectiveness.
– When replacing tires, install the
specified size of tires on all four
wheels.
BRAKE SYSTEM
5-152Starting and driving

–When installing a spare tire, make
sure that it is the proper size and type
as specified on the Tire and Loading
Information label. For additional in-
formation, see “Tire and Loading In-
formation label” (P. 8-28).
– For additional information, see
“Wheels and tires” (P. 8-27).
The ABS controls the brakes so the wheels do
not lock during hard braking or when braking
on slippery surfaces. The system detects the
rotation speed at each wheel and varies the
brake fluid pressure to prevent each wheel
from locking and sliding. By preventing each
wheel from locking, the system helps the
driver maintain steering control and helps to
minimize swerving and spinning on slippery
surfaces.
Using the system
Depress the brake pedal and hold it down.
Depress the brake pedal with firm steady
pressure, but do not pump the brakes. The
Anti-lock Braking System will operate to pre-
vent the wheels from locking up. Steer the
vehicle to avoid obstacles.
WARNING
Do not pump the brake pedal. Doing so may
result in increased stopping distances.
Self-test feature
The Anti-lock Braking System (ABS) includes
electronic sensors, electric pumps, hydraulic
solenoids and a computer. The computer has
a built-in diagnostic feature that tests the
system each time you start the engine and
move the vehicle at a low speed in forward or
reverse. When the self-test occurs, you may
hear a “clunk” noise and/or feel a pulsation in
the brake pedal. This is normal and does not
indicate a malfunction. If the computer
senses a malfunction, it switches the ABS off
and illuminates the ABS warning light on the
instrument panel. The brake system then op-
erates normally but without anti-lock
assistance.
If the ABS warning light illuminates during
the self-test or while driving, have the vehicle
checked. It is recommended that you visit an
INFINITI retailer for this service.
Normal operation
The Anti-lock Braking System (ABS) operates
at speeds above3-6mph(5-10km/h). The
speed varies according to road conditions.
When the ABS senses that one or more
wheels are close to locking up, the actuator
rapidly applies and releases hydraulic pres-
sure. This action is similar to pumping the
brakes very quickly. You may feel a pulsation
in the brake pedal and hear a noise from
under the hood or feel a vibration from the
actuator when it is operating. This is normal
and indicates that the ABS is operating prop-
erly. However, the pulsation may indicate
that road conditions are hazardous and extra
care is required while driving.
BRAKE ASSIST
When the force applied to the brake pedal
exceeds a certain level, the Brake Assist is
activated generating greater braking force
than a conventional brake booster even with
light pedal force.
Starting and driving5-153

Do not attach stickers (including transparent
material), install accessories or apply addi-
tional paint near the sonar sensors.
Do not strike or damage the area around the
sonar sensors. It is recommended that you
visit an INFINITI retailer if the area around
the sonar sensors is damaged due to a
collision.FREEING A FROZEN DOOR LOCK
To prevent a door lock from freezing, apply
de-icer through the key hole. If the lock be-
comes frozen, heat the key before inserting it
into the key hole, or use the INFINITI Intelli-
gent Key.
ANTIFREEZE
In the winter when it is anticipated that the
temperature will drop below 32°F (0°C),
check the antifreeze to assure proper winter
protection. For additional information, see
“Engine cooling system” (P. 8-4).
BATTERY
If the battery is not fully charged during ex-
tremely cold weather conditions, the battery
fluid may freeze and damage the battery. To
maintain maximum efficiency, the battery
should be checked regularly. For additional
information, see “Battery” (P. 8-12).
DRAINING OF COOLANT WATER
If the vehicle is to be left outside without
antifreeze, drain the cooling system, including
the engine block. Refill before operating the
vehicle. For additional information, see
“Changing engine coolant” (P. 8-5).
TIRE EQUIPMENT
1. SUMMER tires have a tread designed toprovide superior performance on dry
pavement. However, the performance of
these tires will be substantially reduced in
snowy and icy conditions. If you operate
your vehicle on snowy or icy roads,
INFINITI recommends the use of MUD &
SNOW or ALL SEASON TIRES on all four
wheels. It is recommended that you visit
an INFINITI retailer for the tire type, size,
speed rating and availability information.
2. For additional traction on icy roads, stud- ded tires may be used. However, some
U.S. states and Canadian provinces pro-
hibit their use. Check local, state and pro-
vincial laws before installing studded tires.
Skid and traction capabilities of studded
snow tires on wet or dry surfaces may be
poorer than that of non-studded snow tires.
3. Tire chains may be used. For additional information, see “Tire chains”(P. 8-36).
COLD WEATHER DRIVING
Starting and driving5-165

Tire and Loading Information label
1Seating capacity: The maximum number
of occupants that can be seated in the
vehicle.
2Original tire size: The size of the tires
originally installed on the vehicle at the
factory.
3Cold tire pressure: Inflate the tires to this
pressure when the tires are cold. Tires are
considered COLD after the vehicle has
been parked for 3 or more hours, or
driven less than 1 mile (1.6 km) at moder-
ate speeds. The recommended cold tire
inflation is set by the manufacturer to provide the best balance of tire wear,
vehicle handling, driveability, tire noise,
etc., up to the vehicle's GVWR.
4Tire size - see “Tire labeling” (P. 8-30).
5Spare tire size.
6Vehicle load limit: see “Vehicle loading
information” (P. 10-15).
Checking tire pressure
WARNING
• Driving at high speeds, 100 mph
(160 km/h) or higher sustained
where it is legal to do so, can cause
tires to have excessive heat build
up, which may result in a tire fail-
ure causing loss of control, crash,
injuries or even death.
LDI3172LDI0393
8-28Do-it-yourself

•Some high-speed rated tires re-
quire inflation pressure adjust-
ment for high-speed operation.
When speed limits and road condi-
tions allow vehicle driving at high
speeds, make sure tires are rated
to support high speed operation,
tires are in optimal conditions and
pressure is adjusted to correct
cold inflation pressure for high
speed operation.
• If your vehicle is equipped with
P235/55RF19 or P255/45RF20
tire sizes, tires require adjustment
to the inflation pressure when
driving the vehicle at speeds of
100 mph (160 km/h) or higher
where it is legal to do so. Set the
cold inflation pressure to 36 psi
(250 kPa). •
After vehicle high speed operation
has ended, readjust the tire pres-
sure to the recommended cold in-
flation pressure. For additional in-
formation, see "Checking tire
pressure" (P. 8-28).
1. Remove the valve stem cap from the tire.
2. Press the pressure gauge squarely onto the valve stem. Do not press
too hard or force the valve stem
sideways, or air will escape. If the
hissing sound of air escaping from
the tire is heard while checking the
pressure, reposition the gauge to
eliminate this leakage.
3. Remove the gauge.
4. Read the tire pressure on the gauge stem and compare to the
specification shown on the Tire
and Loading Information label. 5. Add air to the tire as needed. If too
much air is added, press the core of
the valve stem briefly with the tip
of the gauge stem to release pres-
sure. Recheck the pressure and add
or release air as needed.
6. Install the valve stem cap.
7. Check the pressure of all other tires, including the spare.
8. Check the pressure when driving the vehicle at speeds of 100 mph
(160 km/h) or higher where it is
legal to do so.
Size Cold Tire Infla-
tion Pressure
Front and Rear
Original Tire:
P235/55RF19 33 psi, 230 kPa
Front and Rear
Original Tire:
P255/45RF20 33 psi, 230 kPa
Spare Tire: none
Do-it-yourself8-29

Recommended tire inflation pres-
sures at speeds of 100 mph (160
km/h) or higher where it is legal to do
so.
SizeCold Tire Infla-
tion Pressure
Front and Rear
Original Tire:
P235/55RF19 36 psi, 250 kPa
Front and Rear
Original Tire:
P255/45RF20 36 psi, 250 kPa
Spare Tire: none
TIRE LABELING
Federal law requires tire manufactur-
ers to place standardized information
on the sidewall of all tires. This infor-
mation identifies and describes the
fundamental characteristics of the tire
and also provides the Tire Identifica-
tion Number (TIN) for safety standard
certification. The TIN can be used to
identify the tire in case of a recall.
WDI0394
Example
8-30Do-it-yourself

O1Tire size (example: P215/65R15
95H)
1. P: The “P” indicates the tire is de- signed for passenger vehicles (not
all tires have this information).
2. Three-digit number (215): This number gives the width in millime-
ters of the tire from sidewall edge
to sidewall edge. 3. Two-digit number (65): This num-
ber, known as the aspect ratio,
gives the tire's ratio of height to
width.
4. R: The “R” stands for radial.
5. Two-digit number (15): This num- ber is the wheel or rim diameter in
inches. 6. Two- or three-digit number (95):
This number is the tire's load index.
It is a measurement of how much
weight each tire can support. You
may not find this information on all
tires because it is not required by
law.
7. H: Tire speed rating. You should not drive the vehicle faster than the tire
speed rating.
WDI0395
Example
Do-it-yourself8-31

O2TIN (Tire Identification Number)
for a new tire (example: DOT XX XX
XXX XXXX)
1. DOT: Abbreviation for the “Depart- ment Of Transportation”. The sym-
bol can be placed above, below or
to the left or right of the Tire Iden-
tification Number.
2. Two-digit code: Manufacturer's identification mark. 3. Two-digit code: Tire size.
4. Three-digit code: Tire type code
(Optional).
5. Four numbers represent the week and year the tire was built. For ex-
ample, the numbers 3103 means
the 31st week of 2003. If these
numbers are missing then look on
the other sidewall of the tire.
O3Tire ply composition and material
The number of layers or plies of
rubber-coated fabric in the tire. Tire
manufacturers also must indicate the
materials in the tire, which include
steel, nylon, polyester and others.
O4Maximum permissible inflation
pressure
This number is the greatest amount of
air pressure that should be put in the
tire. Do not exceed the maximum per-
missible inflation pressure.
O5Maximum load rating
This number indicates the maximum
load in kilograms and pounds that can
be carried by the tire. When replacing
the tires on the vehicle, always use a
tire that has the same load rating as
the factory installed tire.
O6Term of “tubeless” or “tube type”
LDI2786
Example
8-32Do-it-yourself

Indicates whether the tire requires an
inner tube (“tube type”) or not
(“tubeless”).
O7The word “radial”
The word “radial” is shown if the tire
has radial structure.
O8Manufacturer or brand name
Manufacturer or brand name is
shown.
Other Tire-related Terminology
In addition to the many terms that are
defined throughout this section, In-
tended Outboard Sidewall is (1) the
sidewall that contains a whitewall,
bears white lettering or bears manu-
facturer, brand, and/or model name
molding that is higher or deeper than
the same molding on the other side-
wall of the tire, or (2) the outward
facing sidewall of an asymmetrical tire that has a particular side that must
always face outward when mounted
on a vehicle.
TYPES OF TIRES
WARNING
• When changing or replacing tires, be sure
all four tires are of the same type (i.e.,
Summer, All Season or Snow) and con-
struction. An INFINITI retailer may be
able to help you with information about
tire type, size, speed rating and
availability.
• Replacement tires may have a lower
speed rating than the factory equipped
tires, and may not match the potential
maximum vehicle speed. Never exceed
the maximum speed rating of the tire.
• Replacing tires with those not originally
specified by INFINITI could affect the
proper operation of the low tire pressure
warning system. •
Always use tires of the same type, size,
brand, construction and tread pattern on
all four wheels. Failure to do so may re-
sult in a circumference difference be-
tween tires on the front and rear axles
which can cause the Vehicle Dynamic
Control (VDC) system to malfunction re-
sulting in personal injury or death, exces-
sive tire wear and may damage the
transmission, transfer case and differen-
tial gears.
• For additional information regarding
tires, refer to “Important Tire Safety In-
formation” (US) or “Tire Safety Informa-
tion” (Canada) in the Warranty Informa-
tion Booklet.
All-Wheel Drive (AWD) models
CAUTION
• ONLY use spare tires specified for the
AWD model.
If excessive tire wear is found, it is recom-
mended that all four tires be replaced with
tires of the same size, brand, construction
and tread pattern. The tire pressure and
wheel alignment should also be checked and
corrected as necessary. It is recommended
that you visit an INFINITI retailer for this
service.
Do-it-yourself8-33