tire size INFINITI Q50 2018 User Guide

JVE0106X
5. Securely store the flat tire and jackingequipment in the vehicle.
6. Place the spare tire cover (if so equipped) and the trunk floor carpeting over the
damaged tire.
7. Close the trunk.
WARNING
. Always make sure that the spare tire
(if so equipped) and jacking equip-
ment are properly secured after use.
Such items can become dangerous
projectiles in an accident or sudden
stop. .
The T-type spare tire and small size
spare tire (if so equipped) are de-
signed for emergency use. See spe-
cific instructions under the heading
“Wheels and tires” (P.8-32). To start your engine with a booster battery,
the instructions and precautions below must
be followed.
WARNING
.
If done incorrectly, jump starting can
lead to a battery explosion, resulting
in severe injury or death. It could also
damage your vehicle.
. Explosive hydrogen gas is always
present in the vicinity of the battery.
Keep all sparks and flames away from
the battery.
. Do not allow battery fluid to come
into contact with eyes, skin, clothing
or painted surfaces. Battery fluid is a
corrosive sulphuric acid solution
which can cause severe burns. If the
fluid should come into contact with
anything, immediately flush the con-
tacted area with water.
. Keep the battery out of the reach of
children.
. The booster battery must be rated at
12 volts. Use of an improperly rated
battery can damage your vehicle.
. Whenever working on or near a
battery, always wear suitable eye
protectors (for example, goggles or
In case of emergency6-9
JUMP STARTING

8-34Do-it-yourself
SDI2567
Tire and Loading Information label
Seating capacity: The maximum
number of occupants that can be
seated in the vehicle.
Vehicle load limit: See “Vehicle
loading information” (P.10-19).
Original size: The size of the tires
originally installed on the vehicle
at the factory.
Cold tire pressure: Inflate the
tires to this pressure when the
tires are cold. Tires are consid-ered COLD after the vehicle has
been parked for 3 or more hours,
or driven less than 1 mile (1.6 km)
at moderate speeds. The recom-
mended 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.
Tire size — see “Tire labeling”
(P.8-36).
Spare tire size or compact spare
tire size (if so equipped)

SDI1949
Checking the tire pressure
1. Remove the valve stem cap fromthe 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 it 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
pressure. 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.
SIZE COLD
TIRE IN- FLA-
TION
PRES- SURE
FRONT ORIGI- NAL
TIRE P225/55R-
F17 95V
240 kPa,
35 PSI
P225/50R-
F18 94V 240 kPa,
35 PSI
P245/40R-
F19 94V 240 kPa,
35 PSI
245/40RF19
94W 240 kPa,
35 PSI
245/40R19
94Y 240 kPa,
35 PSI
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REAR
ORIGI- NAL
TIRE P225/55R-
F17 95V
240 kPa,
35 PSI
P225/50R-
F18 94V 240 kPa,
35 PSI
P245/40R-
F19 94V 240 kPa,
35 PSI
245/40RF19
94W 240 kPa,
35 PSI
265/35R19
94W 240 kPa,
35 PSI
265/35RF19
94W 240 kPa,
35 PSI
SPARE
TIRE (if
so
equip- ped) T145/70R18
107M
420 kPa,
60 PSI
SDI1575
Example
TIRE LABELING
Federal law requires tire manufac-
turers to place standardized informa-
tion on the sidewall of all tires. This
information identifies and describes
the fundamental characteristics of
the tire and also provides the tire
identification number (TIN) for safety
standard certification. The TIN can be
used to identify the tire in case of a
recall.
SDI1606
ExampleTire size (example: P215/60R16
94H)
1. P: The “P” indicates the tire is designed for passenger vehicles.
(Not all tires have this informa-
tion.)
2. Three-digit number (215): This number gives the width in milli-
meters of the tire from sidewall
edge to sidewall edge.
3. Two-digit number (60): This num- ber, known as the aspect ratio,
gives the tire’s ratio of height to

width.
4. R: The “R” stands for radial. F: The “F” after “R” indicates Self-
Supporting type run-flat tire.
5. Two-digit number (16): This num- ber is the wheel or rim diameter in
inches.
6. Two- or three-digit number (94): 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.
JVM0694X
ExampleTIN (Tire Identification Number) for
a new tire (example: DOT XX XX XXX
XXXX)
1. DOT: Abbreviation for the “De- partment of Transportation”. The
symbol can be placed above, be-
low or to the left or right of the
Tire Identification 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
example, the numbers 3103
means the 31st week of 2003. If
these numbers are missing, then
look on the other sidewall of the
tire.
Tire 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.
Maximum permissible inflation
pressure
This number is the greatest amount of
air pressure that should be put in the
tire. Do not exceed the maximum
permissible inflation pressure.
Maximum 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.
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Term of “tubeless” or “tube type”
Indicates whether the tire requires an
inner tube (“tube type”) or not (“tube-
less”).
The word “radial”
The word “radial” is shown, if the tire
has radial structure.
Manufacturer 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
(Example: Summer, All Season or
Snow) and construction. 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 origin-
ally specified by INFINITI could affect
the proper operation of the TPMS.
. For additional information regarding
tires, refer to “Important Tire Safety
Information” (US) or “Tire Safety
Information” (Canada) in the War-
ranty Information Booklet.
All season tires
INFINITI specifies all season tires on some
models to provide good performance all year, including snowy and icy road condi-
tions. All Season tires are identified by ALL
SEASON and/or M&S (Mud and Snow) on
the tire sidewall. Snow tires have better
snow traction than All Season tires and may
be more appropriate in some areas.
Summer tires
INFINITI specifies summer tires on some
models to provide superior performance on
dry roads. Summer tire performance is
substantially reduced in snow and ice. Sum-
mer 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
handling of your vehicle.
Generally, snow tires will have lower speed
ratings 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
pattern on all four wheels.
For additional traction on icy roads, studded
tires may be used. However, some U.S.
states and Canadian provinces prohibit their
use. Check local, state and provincial 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.
Run-flat tires (if so equipped)
Your vehicle is equipped with run-flat tires.
You can continue driving to a safe location
even if they are punctured. Always use run-
flat tires of the specified size on all four
wheels. Mixing tire sizes or construction may
reduce vehicle handling stability. If neces-
sary, contact an INFINITI retailer for assis-
tance.
Frequently check the tire pressure and adjust
pressure of each tire properly. The tire
pressure can be also checked in the vehicle
information display.
It can be difficult to tell if a run-flat tire is
under-inflated or flat. Check the tire pres-
sures as described earlier in this section. If
the tire becomes under-inflated while driv-
ing, the low tire pressure warning light will
illuminate. If the tire becomes flat while
driving, the low tire pressure warning lightand 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.
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
indication 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
necessary. It is recommended you visit an
INFINITI retailer for these services. Even if
the tire is inflated to the specified COLD tire
pressure, the warning light will continue to
illuminate until the system is reset.
If the low tire pressure warning light illumi-
nates continuously and the “Flat Tire - Visit
dealer” warning appears in the vehicle
information 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 a punctured run-flat tire, re-
member that vehicle handling stabi-
lity is reduced, which could lead to an
accident and personal 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 distance the vehicle
can be driven on a flat tire depends on
outside temperature, vehicle load,
road 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
vibrations while driving with a punc-
tured run-flat tire, pull off the road
to a safe location and stop the vehicle
as soon as possible. The tire may be
seriously damaged and need to be
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8-40Do-it-yourself
replaced.
CAUTION
.Never install tire chains on a punctu-
red run-flat tire, as this could damage
your vehicle.
. Avoid driving over any projection or
pothole, as the clearance between
the vehicle and the ground is smaller
than normal.
. Do not enter an automated car wash
with a punctured run-flat tire.
. It is recommended you have the
punctured tire inspected by an
INFINITI retailer or other authorized
repair shop. Replace the tire as soon
as possible if the tire is seriously
damaged.
TIRE CHAINS
CAUTION
Tire chains/cables should not be in-
stalled on 265/35R19 and
265/35RF19 tires. Doing so will cause
damage to the vehicle. If you plan to use
tire chains/cables, you should install
245/45RF19 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 re-
stricted tire to vehicle clearance. Vehicles
that can use Class “S” chains are designed to
meet the SAE standard minimum clearances
between the tire and the closest vehicle
suspension or body component required to
accommodate the use of a winter traction
device (tire chains or cables). The minimum
clearances are determined using the factory
equipped tire size. Other types may damage
your vehicle. Use chain tensioners when
recommended by the tire chain manufac-
turer to ensure a tight fit. Loose end links of the tire chain must be secured or removed to
prevent the possibility of whipping action
damage to the fenders or underbody. If
possible, avoid fully loading your vehicle
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.
Tire chains must be installed only on the
rear wheels and not on the front wheels.
Never install tire chains on a TEMPORARY
USE ONLY spare tire (if so equipped). Never
install tire chains on a punctured run-flat tire
(if so equipped), as this could damage your
vehicle.
Do not use tire chains on dry roads. Driving
with tire chains in such conditions can cause
damage to the various mechanisms of the
vehicle due to some overstress.

SDI1662
CHANGING WHEELS AND TIRES
Tire rotation (models equipped with
same size tires on all wheels)
INFINITI recommends rotating the
tires every 5,000 miles (8,000 km).
(See “Flat tire” (P.6-3) for tire repla-
cing procedures.)
As soon as possible, tighten the
wheel nuts to the specified torque
with a torque wrench.Wheel nut tightening torque:80 ft-lb (108 N·m) The wheel nuts must be kept tigh-
tened to the specification at all times.
It is recommended that wheel nuts be
tightened to the specification at each
tire rotation interval.
WARNING
.
After rotating the tires, check
and adjust the tire pressure.
. Retighten the wheel nuts when
the vehicle has been driven for
600 miles (1,000 km) (also in
cases of a flat tire, etc.).
. Do not include the T-type spare
tire or any other small size
spare tire in the tire rotation.
. For additional information re-
garding tires, refer to “Impor-
tant Tire Safety Information”
(US) or “Tire Safety Informa-
tion” (Canada) in the Warranty
Information Booklet.
After the ignition switch is placed in
the ON position, it may take a period of time for the tire pressure to be
displayed in the vehicle information
display while the vehicle is driven.
Depending on the radio wave circum-
stance, tire pressure may not cor-
rectly be displayed.
Tire rotation (models equipped with
different size tires on front and rear)
Tires cannot be rotated on this vehi-
cle, as front tires are a different size
from rear tires.
A pin is on the front brake rotor to
prevent the rear wheels from being
installed in place of the front wheels.
The spare tire can be installed in place
of the front and rear wheels. When
installing the spare tire in the front
wheel, the hole in the spare tire wheel
must be aligned with the pin on the
brake rotor.
WARNING
.
If your vehicle is equipped with
different size front and rear
tires, never install the rear
Do-it-yourself8-41

.The original tires have built-in
tread wear indicators. When
wear indicators are visible, the
tire(s) should be replaced.
. Tires degrade with age and use.
Have tires, including the spare,
over 6 years old checked by a
qualified technician, because
some tire damage may not be
obvious. Replace the tires as
necessary to prevent tire failure
and possible personal injury.
. Improper service of the spare
tire may result in serious perso-
nal injury. If it is necessary to
repair the spare tire, it is re-
commended you visit an
INFINITI retailer for this ser-
vice.
. For additional information re-
garding tires, refer to “Impor-
tant Tire Safety Information”
(US) or “Tire Safety Informa-
tion” (Canada) in the Warranty
Information Booklet.Replacing wheels and tires
When replacing a tire, use the same size,
tread design, speed rating and load carrying
capacity as originally equipped. (See “Speci-
fications” (P.10-11) for recommended types
and sizes of tires and wheels.)
After the ignition switch is placed in the ON
position, it may take a period of time for the
tire pressure to be displayed in the vehicle
information display while the vehicle is
driven. Depending on the radio wave circum-
stance, tire pressure may not correctly be
displayed.
WARNING
. The use of tires other than those
recommended or the mixed use of
tires of different brands, construc-
tion (bias, bias-belted, radial or run-
flat), or tread patterns can adversely
affect the ride, braking, handling,
ground clearance, body-to-tire clear-
ance, tire chain clearance, speed-
ometer calibration, headlight aim
and bumper height. Some of these
effects may lead to accidents and
could result in serious personal injury.
. For Two-Wheel Drive (2WD) models,
if your vehicle was originally equipped with 4 tires that were the
same size and you are only replacing
2 of the 4 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 condi-
tions 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 dimen-
sion. Wheels of a different off-set
could cause premature tire wear,
degrade vehicle handling character-
istics and/or interference with the
brake discs/drums. Such interference
can lead to decreased braking effi-
ciency and/or early brake pad/shoe
wear. See “Wheels and tires” (P.10-
12) of this manual for wheel off-set
dimensions.
. Since the spare tire is not equipped
with the TPMS, when a spare tire is
mounted or a wheel is replaced, 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 you visit an INFINITI
retailer for these services.
Do-it-yourself8-43