wheel size INFINITI QX50 2020 User Guide

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, becareful when braking, accelerating or
downshifting. Abrupt braking or acceler-
ating 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 cor-
rectly.
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 techniques.
It can help maintain vehicle control dur-
ing braking on slippery surfaces. Remem-
ber that stopping distances on slippery
surfaces will be longer than on normal
surfaces even with ABS. Stopping dis-
tances may also be longer on rough,
gravel or snow covered roads, or if you
are using tire chains. Always maintain a
safe distance from the vehicle in front of
you. Ultimately, the driver is responsible
for safety.
∙ Tire type and condition may also affect braking effectiveness.
– When replacing tires, install the speci- fied size of tires on all four wheels.
BRAKE SYSTEM
5-180Starting and driving

– When installing a spare tire, make surethat it is the proper size and type as
specified on the Tire and Loading In-
formation label. For additional infor-
mation, refer to “Tire and Loading In-
formation label” in the “Technical and
consumer information” section of this
manual.
– For additional information, refer to “Wheels and tires” in the “Do-it-
yourself” section of this manual.
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 assis-
tance.
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.
WARNING
The Brake Assist is only an aid to assist
braking operation and is not a collision
warning or avoidance device. It is the driv-
er’s responsibility to stay alert, drive safely
and be in control of the vehicle at all times.
Starting and driving5-181

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, refer to
“Changing engine coolant” in the “Do-it-
yourself” section of this manual.
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 oper-
ate 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 infor-
mation.
2. For additional traction on icy roads, studded tires may be used. However,
some U.S. states and Canadian prov-
inces prohibit their use. Check local,
state and provincial laws before install-
ing 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, refer to “Tire chains” in the
“Do-it-yourself” section of this manual.
SPECIAL WINTER EQUIPMENT
It is recommended that the following items
be carried in the vehicle during winter:
∙ A scraper and stiff-bristled brush to re- move ice and snow from the windows
and wiper blades.
∙ A sturdy, flat board to be placed under the jack to give it firm support.
∙ A shovel to dig the vehicle out of snow- drifts.
∙ Extra washer fluid to refill the windshield-washer fluid reservoir.
DRIVING ON SNOW OR ICE
WARNING
∙ Wet ice (32°F, 0°C and freezing rain),very cold snow or ice can be slick and very
hard to drive on. The vehicle will have
much less traction or “grip” under these
conditions. Try to avoid driving on wet
ice until the road is salted or sanded.
∙ Whatever the condition, drive with cau- tion. Accelerate and slow down with
care. If accelerating or downshifting too
fast, the drive wheels will lose even more
traction.
∙ Allow more stopping distance under these conditions. Braking should be
started sooner than on dry pavement.
∙ Allow greater following distances on slippery roads.
∙ Watch for slippery spots (glare ice). These may appear on an otherwise clear
road in shaded areas. If a patch of ice is
seen ahead, brake before reaching it. Try
not to brake while on the ice, and avoid
any sudden steering maneuvers.
∙ Do not use the cruise control on slippery roads.
5-192Starting and driving

1Tire 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 in-
dex. It is a measurement of how
much weight each tire can sup-
port. You may not find this infor-
mation 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.
Example
WDI0395
Do-it-yourself8-29

7The word “radial”
The word “radial” is shown if the tire
has radial structure.
8Manufacturer 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 result
in a circumference difference between
tires on the front and rear axles which can
cause the Vehicle Dynamic Control (VDC)
system to malfunction resulting in per-
sonal injury or death, excessive tire wear
and may damage the transmission, trans-
fer case and differential 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.
All season tires
INFINITI specifies All Season tires on some
models to provide good performance all year,
including snowy and icy road conditions. All
Season tires are identified by ALL SEASON
and/or M&S on the tire sidewall. Snow tires
have better snow traction than All Season
tires and may be more appropriate in some
areas.
Do-it-yourself8-31

Summer tires
INFINITI specifies summer tires on some
models to provide superior performance on
dry roads. Summer tire performance is sub-
stantially reduced in snow and ice. Summer
tires do not have the tire traction rating
“M&S” on the tire sidewall.
If you plan to operate your vehicle in snowy or
icy conditions, INFINITI recommends the use
of SNOW tires or ALL SEASON tires on all
four wheels.
Snow tires
If snow tires are needed, it is necessary to
select tires equivalent in size and load rating
to the original equipment tires. If you do not,
it can adversely affect the safety and han-
dling of your vehicle.
Generally, snow tires have lower speed rat-
ings than factory equipped tires and may not
match the potential maximum vehicle speed.
Never exceed the maximum speed rating of
the tire.
If you install snow tires, they must be the
same size, brand, construction and tread pat-
tern on all four wheels.
For additional traction on icy roads, studded
tires may be used. However, some U.S. statesand Canadian provinces prohibit their use.
Check local, state and provincial laws before
installing studded tires. Skid and traction ca-
pabilities of studded snow tires on wet or dry
surfaces may be poorer than that of non-
studded snow tires.
Run–flat tires
Your vehicle is equipped with run-flat tires
and is not equipped with a spare tire, or a jack
and tool kit. The jack and tool kit may be
purchased at the dealer. Please consult an
INFINITI retailer for additional information.
You can continue driving to a safe location
even if the run-flat tires are punctured. Al-
ways use run-flat tires of the specified size on
all four wheels. Mixing tire sizes or construc-
tion may reduce vehicle handling stability. If
necessary, it is recommended that you visit an
INFINITI retailer for this service.
Frequently check the tire pressure and adjust
pressure of each tire properly. The tire pres-
sure can be also checked in the vehicle infor-
mation display.
It can be difficult to tell if a run-flat tire is
under-inflated or flat. Check the tire pres-
sures as described in this section. If the tire
becomes under-inflated while driving, the
low tire pressure warning light will illuminate
and the “Tire Pressure Low – Add Air” warn-
ing appears in the vehicle information display.
If the tire becomes flat while driving, the low
tire pressure warning light and the “Flat Tire –
Visit dealer" warning will appear.
Low tire pressure:
If the vehicle is being driven with low tire
pressure, the low tire pressure warning light
will illuminate and the “Tire Pressure Low –
Add Air” warning appears in the vehicle infor-
mation display.
Flat tire:
If the vehicle is being driven with one or more
flat tires, the low tire pressure warning light
will illuminate continuously and a chime will
sound for 10 seconds. A “Flat-Tire – Visit
dealer" warning also appears in the vehicle
information display.
The chime will only sound at the first indica-
tion of a flat tire and the warning light will
illuminate continuously. When the flat tire
warning is activated, have the system reset
and the tire checked and replaced if neces-
sary. It is recommended that you visit an
INFINITI retailer for this service. Even if the
tire is inflated to the specified COLD tire
pressure, the warning light will continue to
illuminate until the system is reset. It is recom-
mended that you visit an INFINITI retailer for
this service.
8-32Do-it-yourself

If the low tire pressure warning light illumi-
nates continuously and the “Flat Tire – Visit
dealer" warning appears in the vehicle infor-
mation display:∙ Do not exceed 50 mph (80 km/h).
∙ Increase your following distance to allow for increased stopping distances.
∙ Avoid sudden maneuvers, hard cornering and hard braking.
WARNING
∙ Although you can continue driving with apunctured run-flat tire, remember that
vehicle handling stability is reduced,
which could lead to an accident and per-
sonal injury. Also, driving a long distance
at high speeds may damage the tire.
∙ Do not drive at speeds above 50 mph (80 km/h) and do not drive more than
approximately 93 miles (150 km) with a
punctured run-flat tire. The actual dis-
tance the vehicle can be driven on a flat
tire depends on outside temperature, ve-
hicle load, read conditions and other
factors.
∙ Drive safely at reduced speeds. Avoid hard cornering or braking, which may
cause you to lose control of the vehicle. ∙ If you detect any unusual sounds or vi-
brations while driving with a punctured
run-flat tire, pull off the road to a safe
location and stop the vehicle as soon as
possible. The tire may be seriously dam-
aged and need to be replaced.
CAUTION
∙ Never install tire chains on a puncturedrun-flat tire, as this could damage your
vehicle.
∙ Avoid driving over any projection or pot- hole, as the clearance between the ve-
hicle and the ground is smaller than
normal.
∙ Do not enter an automated car wash with a punctured run-flat tire.
∙ Have the punctured tire inspected by an INFINITI retailer or other authorized re-
pair shop. Replace the tire as soon as pos-
sible if the tire is seriously damaged. ∙ Always use tires of the same type, size,
brand, construction (bias, bias-belted or
radial), and tread pattern on all four
wheels. Failure to do so may result in a
circumference difference between tires
on the front and rear axles which will
cause excessive tire wear and may dam-
age the transmission, transfer case and
differential gears (AWD models).
∙ 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, con-
struction 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

TIRE CHAINS
CAUTION
Tire chains/cables should not be installed
on P255/45RF20 size tires. Installation of
the tire chains/cables on P255/45RF20
size tires will cause damage to the vehicle. If
you plan to use tire chains/cables, you
should install P235/55RF19 size tires on
your vehicle.
Use of tire chains may be prohibited accord-
ing to location. Check the local laws before
installing tire chains. When installing tire
chains, make sure they are the proper size for
the tires on your vehicle and are installed
according to the chain manufacturer’s sug-
gestions. Use only SAE class “S” chains. Class
“S” chains are used on vehicles with restricted
tire to vehicle clearance. Vehicles that can use
Class “S” chains are designed to meet the
minimum clearances between the tire and the
closest vehicle suspension or body compo-
nent required to accommodate the use of a
winter traction device (tire chains or cables).
The minimum clearances are determined us-
ing the factory equipped tire size. Other types
may damage your vehicle. Use chain tension-
ers when recommended by the tire chain
manufacturer to ensure a tight fit. Loose end
links of the tire chain must be secured or removed to prevent the possibility of whip-
ping action damage to the fenders or under-
body. If possible, avoid fully loading your ve-
hicle when using tire chains. In addition, drive
at a reduced speed. Otherwise, your vehicle
may be damaged and/or vehicle handling
and performance may be adversely affected.
Do not use tire chains on dry roads. Driving
with chains in such conditions can cause
damage to the various mechanisms of the
vehicle due to some overstress.
CHANGING WHEELS AND TIRES
Tire rotation
INFINITI recommends rotating the
tires every 7,500 miles (12,000 km).
For additional information on tire re-
placing procedures, refer to “Flat tire”
in the “In case of emergency” section
of this manual.
As soon as possible, tighten the wheel
nuts to the specified torque with a
torque wrench.
WDI0258
8-34Do-it-yourself

Replacing wheels and tires
When replacing a tire, use the same size,
tread design, speed rating and load carrying
capacity as originally equipped. For addi-
tional information, refer to “Wheels and tires”
in the “Technical and consumer information”
section of this manual.
WARNING
∙ The use of tires other than those recom-mended or the mixed use of tires of dif-
ferent brands, construction (bias, bias-
belted or radial), or tread patterns can
adversely affect the ride, braking, han-
dling, VDC system, ground clearance,
body-to-tire clearance, tire chain clear-
ance, speedometer calibration, headlight
aim and bumper height. Some of these
effects may lead to accidents and could
result in serious personal injury.
∙ For 2WD models, if your vehicle was originally equipped with four tires that
were the same size and you are only re-
placing two of the four tires, install the
new tires on the rear axle. Placing new
tires on the front axle may cause loss of
vehicle control in some driving conditions
and cause an accident and personal
injury. ∙ If the wheels are changed for any reason,
always replace with wheels which have
the same off-set dimension. Wheels of a
different off-set could cause premature
tire wear, degrade vehicle handling char-
acteristics, affect the VDC system
and/or interference with the brake discs.
Such interference can lead to decreased
braking efficiency and/or early brake
pad wear. For additional information on
wheel off-set dimensions, refer to
“Wheels and tires” in the “Technical and
consumer information” section of this
manual.
∙ When replacing a wheel without the TPMS, such as the spare tire, the TPMS
will not function and the low tire pressure
warning light will flash for approximately
1 minute. The light will remain on after
1 minute. Have your tires replaced
and/or TPMS system reset as soon as
possible. It is recommended that you visit
an INFINITI retailer for this service.
∙ Replacing tires with those not originally specified by INFINITI could affect the
proper operation of the TPMS.
∙ The TPMS sensor may be damaged if it is not handled correctly. Be careful when
handling the TPMS sensor. ∙ When replacing the TPMS sensor, the ID
registration may be required. It is recom-
mended that you visit an INFINITI re-
tailer for ID registration.
∙ Do not use a valve stem cap that is not specified by INFINITI. The valve stem cap
may become stuck.
∙ Be sure that the valve stem caps are cor- rectly fitted. Otherwise the valve may be
clogged up with dirt and cause a malfunc-
tion or loss of pressure.
∙ Do not install a damaged or deformed wheel or tire even if it has been repaired.
Such wheels or tires could have structural
damage and could fail without warning.
∙ The use of retread tires is not recommended.
∙ 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.
Wheel balance
Unbalanced wheels may affect vehicle han-
dling and tire life. Even with regular use,
wheels can get out of balance. Therefore,
they should be balanced as required.
8-36Do-it-yourself

When driving in areas using road salt or other
corrosive materials, check lubrication fre-
quently.
Lights*:Clean the headlights on a regular
basis. Make sure that the headlights, stop
lights, tail lights, turn signal lights, and other
lights are all operating properly and installed
securely. Also check headlight aim.
Road wheel nuts (lug nuts)*: When checking
the tires, make sure no wheel nuts are miss-
ing, and check for any loose wheel nuts.
Tighten if necessary.
Tire rotation*: Tires should be rotated every
7,500 miles (12,000 km). If your vehicle is
equipped with different sized tires in the front
and rear, tires cannot be rotated.
Tires*: Check the pressure with a gauge of-
ten and always prior to long distance trips. If
necessary, adjust the pressure in all tires, in-
cluding the spare, to the pressure specified.
Check carefully for damage, cuts or excessive
wear.
Tire Pressure Monitoring System (TPMS)
transmitter components: Replace the TPMS
transmitter grommet seal, valve core and cap
when the tires are replaced due to wear or
age. Wheel alignment and balance:
If the vehicle
should pull to either side while driving on a
straight and level road, or if you detect un-
even or abnormal tire wear, there may be a
need for wheel alignment.
If the steering wheel or seat vibrates at nor-
mal highway speeds, wheel balancing may be
needed.
For additional information regarding tires, re-
fer to “Important Tire Safety Information”
(US) or “Tire Safety Information” (Canada) in
the INFINITI Warranty Information Booklet.
Windshield: Clean the windshield on a regular
basis. Check the windshield at least every six
months for cracks or other damage. Have a
damaged windshield repaired by a qualified
repair facility. It is recommended that you have
a damaged windshield repaired by an INFINITI
retailer, or a INFINITI Certified Collision Cen-
ter. To locate a collision center in your area,
refer to http://collision.infinitiusa.com.
Windshield wiper blades*: Check for cracks
or wear if they do not wipe properly.
Inside the vehicle
The maintenance items listed here should be
checked on a regular basis, such as when
performing scheduled maintenance, cleaning
the vehicle, etc. Accelerator pedal:
Check the pedal for
smooth operation and make sure the pedal
does not catch or require uneven effort. Keep
the floor mat away from the pedal.
Brake pedal: Check the pedal for smooth op-
eration. If the brake pedal suddenly goes
down further than normal, the pedal feels
spongy or the vehicle seems to take longer to
stop, have your vehicle checked immediately.
It is recommended that you visit an INFINITI
retailer for this service. Keep the floor mat
away from the pedal.
Brakes: Check that the brakes do not pull the
vehicle to one side when applied.
Continuously Variable Transmission (CVT) P
(Park) position mechanism: On a fairly steep
hill check that the vehicle is held securely with
the shift lever in the P (Park) position without
applying any brakes.
Parking brake: Check the parking brake op-
eration regularly. The vehicle should be se-
curely held on a fairly steep hill with only the
parking brake applied. If the parking brake
does not securely hold the vehicle, it is recom-
mended that you visit an INFINITI retailer for
service.
Maintenance and schedules9-3