2018 INFINITI Q50 tire size

5-142Starting and driving
Intelligent All-Wheel Drive (AWD)
models
If you install snow tires, they must also be
the same size, brand, construction and tread
pattern on all four wheels.
SPECIAL WINTER EQUIPMENT
It is recommended that the following items
be carried in the vehicle during winter:
.A scraper and stiff-bristled brush to
remove 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
snowdrifts.
. Extra window washer fluid to refill the
reservoir tank.
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
caution. Accelerate and slow down
with care. If accelerating or down-
shifting 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 pave-
ment.
. 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 steer-
ing maneuvers.
. Do not use the cruise control on
slippery roads.
. Snow can trap dangerous exhaust
gases under your vehicle. Keep snow
clear of the exhaust pipe and from
around your vehicle.
ENGINE BLOCK HEATER (if so
equipped)
Engine block heaters are used to assist in
cold temperature starting.
The engine block heater should be used
when the outside temperature is 20°F
(−7°C) or lower.
To use the engine block heater
1. Turn the engine off.
2. Open the hood and unwrap the engine
block heater cord.
3. Plug the engine block heater cord into a grounded 3-wire, 3-pronged extension
cord.
4. Plug the extension cord into a Ground Fault Interrupt (GFI) protected,
grounded 110-volt AC (VAC) outlet.
5. The engine block heater must be plugged in for at least 2 - 4 hours, depending on
outside temperatures, to properly warm
the engine coolant. Use an appropriate
timer to turn the engine block heater on.
6. Before starting the engine, unplug and properly store the cord to keep it away
from moving parts.

6-8In case of emergency
SCE0661
Installing the spare tire
The T-type spare tire (if so equipped) is
designed for emergency use. (See specific
instructions under the heading “Wheels and
tires” (P.8-32).)
1. Clean any mud or dirt from the surfacebetween the wheel and hub.
2. Carefully put the spare tire on and tighten the wheel nuts finger tight.
Models equipped with different sized
tires in the front and rear:
When replacing a front tire, make sure
that the hole in the spare tire wheel is
aligned with the pin on the brake rotor. 3. With the wheel nut wrench, tighten
wheel nuts alternately and evenly in the
sequence illustrated (
,,,,) until
they are tight.
4. Lower the vehicle slowly until the tire touches the ground. Then, with the
wheel nut wrench, tighten the wheel
nuts securely in the sequence as illu-
strated. Lower the vehicle completely.
WARNING
.Incorrect wheel nuts or improperly
tightened wheel nuts can cause the
wheel to become loose or come off.
This could cause an accident.
. Do not use oil or grease on the wheel
studs or nuts. This could cause the
nuts to become loose.
. Retighten the wheel nuts when the
vehicle has been driven for 600 miles
(1,000 km) (also in cases of a flat tire,
etc.).
.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 specification at all times. It
is recommended that wheel nuts be
tightened to specifications at each
lubrication interval.
.Adjust tire pressure to the COLD
pressure.
COLD pressure:
After the vehicle has been parked for
three hours or more or driven less
than 1 mile (1.6 km).
COLD tire pressures are shown on
the Tire and Loading Information
label affixed to the driver side center
pillar.

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
Do-it-yourself8-35

8-36Do-it-yourself
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.
Do-it-yourself8-37

8-38Do-it-yourself
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