2018 INFINITI Q50 wheel size

1-42Safety — Seats, seat belts and supplemental restraint system
JVR0192X
7. If the booster seat is installed in the frontpassenger seat, push the ignition switch
to the ON position. The front passenger
air bag status light
may or may not
illuminate depending on the size of the
child and the type of booster seat used.
See “Front passenger air bag and status
light” (P.1-50).
PRECAUTIONS ON SUPPLE-
MENTAL RESTRAINT SYSTEM
This Supplemental Restraint System (SRS)
section contains important information con-
cerning the following systems:
. Driver and passenger front-impact sup-
plemental air bags (INFINITI Advanced
Air Bag System)
. Front seat-mounted side-impact supple-
mental air bag
. Roof-mounted curtain side-impact and
rollover supplemental air bag
. Seat belt with pretensioner
Supplemental front-impact air bag system:
The INFINITI Advanced Air Bag System can
help cushion the impact force to the head
and chest of the driver and front passenger
in certain frontal collisions.
Front seat-mounted side-impact supple-
mental air bag system: This system can help
cushion the impact force to the chest and
pelvis area of the driver and front passenger
in certain side impact collisions. The side air
bag is designed to inflate on the side where
the vehicle is impacted.
Roof-mounted curtain side-impact and roll-
over supplemental air bag system: This
system can help cushion the impact force
to the head of occupants in front and rear
outboard seating positions in certain side impact or rollover collisions. In a side impact,
the curtain air bags are designed to inflate
on the side where the vehicle is impacted. In
a rollover, the curtain air bags on both sides
are designed to inflate and remain inflated
for a short time.
Curtain air bags are also designed to inflate
in certain types of rollover collisions or near
rollovers. As a result, certain vehicle move-
ments may cause the curtain air bags to
inflate.
These supplemental restraint systems are
designed to
supplement the crash protection
provided by the driver and passenger seat
belts and are not a substitute for them. Seat
belts should always be correctly worn and
the occupant seated a suitable distance
away from the steering wheel, instrument
panel and door finishers. (See “Seat belts”
(P.1-12) for instructions and precautions on
seat belt usage.)
The supplemental air bags operate only
when the ignition switch is in the ON
position.
After pushing the ignition switch to the ON
position, the supplemental air bag warning
light illuminates. The supplemental air bag
warning light will turn off after about 7
seconds if the systems are operational.
SUPPLEMENTAL RESTRAINT SYSTEM

WARNING
.Radio waves could adversely affect
electric medical equipment. Those
who use a pacemaker should contact
the electric medical equipment man-
ufacturer for the possible influences
before use.
. If the light does not illuminate with
the ignition switch pushed ON, have
the vehicle checked as soon as possi-
ble. It is recommended you visit an
INFINITI retailer for this service.
. If the light illuminates while driving,
avoid sudden steering maneuvers or
abrupt braking, reduce vehicle speed,
pull off the road to a safe location
and stop the vehicle as soon as
possible. Driving with under-inflated
tires may permanently damage the
tires and increase the likelihood of
tire failure. Serious vehicle damage
could occur and may lead to an
accident and could result in serious
personal injury. Check the tire pres-
sure for all four tires. Adjust the tire
pressure to the recommended COLD
tire pressure shown on the Tire and
Loading Information label to turn the
low tire pressure warning light OFF.
If the light still illuminates while driving after adjusting the tire pres-
sure, a tire may be flat or the TPMS
may be malfunctioning. If you have a
flat tire, replace it with a spare tire (if
so equipped) as soon as possible. If no
tire is flat and all tires are properly
inflated, it is recommended you con-
sult an INFINITI retailer.
. For models with run-flat tires,
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 tires.
— 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.
— If you detect any unusual sounds or vibrations while driving with a
punctured run-flat tire, pull off
the road to a safe location and
stop the vehicle as soon as possi-
ble. The tire may be seriously damaged and need to be replaced.
. 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 the 1 minute.
Have your tires replaced and/or
TPMS system reset as soon as pos-
sible. It is recommended you visit an
INFINITI retailer for these services.
. Replacing tires with those not origin-
ally specified by INFINITI could affect
the proper operation of the TPMS.
CAUTION
.The TPMS is not a substitute for the
regular tire pressure check. Be sure to
check the tire pressure regularly.
. If the vehicle is being driven at speeds
of less than 16 MPH (25 km/h), the
TPMS may not operate correctly.
. Be sure to install the specified size of
tires to the four wheels correctly.
Instruments and controls2-13

5-10Starting and driving
damage. See “Wheels and tires” (P.8-32) of
this manual.
If a tire rapidly loses air pressure or “blows-
out” while driving maintain control of the
vehicle by following the procedure below.
Please note that this procedure is only a
general guide. The vehicle must be driven as
appropriate based on the conditions of the
vehicle, road and traffic.
WARNING
The following actions can increase the
chance of losing control of the vehicle if
there is a sudden loss of tire air pressure.
Losing control of the vehicle may cause a
collision and result in personal injury.
.The vehicle generally moves or pulls
in the direction of the flat tire.
. Do not rapidly apply the brakes.
. Do not rapidly release the accelerator
pedal.
. Do not rapidly turn the steering
wheel.
1. Remain calm and do not overreact.
2. Maintain a firm grip on the steering wheel with both hands and try to hold
a straight course. 3. When appropriate, slowly release the
accelerator pedal to gradually slow the
vehicle.
4. Gradually steer the vehicle to a safe location off the road and away from
traffic if possible.
5. Lightly apply the brake pedal to gradu- ally stop the vehicle.
6. Turn on the hazard warning flashers and either contact a roadside emergency
service to change the tire or see “Chan-
ging a flat tire” (P.6-4) of this Owner’s
Manual.
DRINKING ALCOHOL/DRUGS
AND DRIVING
WARNING
Never drive under the influence of alco-
hol or drugs. Alcohol in the bloodstream
reduces coordination, delays reaction
time and impairs judgement. Driving
after drinking alcohol increases the like-
lihood of being involved in an accident
injuring yourself and others. Addition-
ally, if you are injured in an accident,
alcohol can increase the severity of the
injury. INFINITI is committed to safe driving. How-
ever, you must choose not to drive under the
influence of alcohol. Every year thousands of
people are injured or killed in alcohol-related
accidents. Although the local laws vary on
what is considered to be legally intoxicated,
the fact is that alcohol affects all people
differently and most people underestimate
the effects of alcohol.
Remember, drinking and driving don’t mix!
And that is true for drugs, too (over-the-
counter, prescription, and illegal drugs).
Don’t drive if your ability to operate your
vehicle is impaired by alcohol, drugs, or some
other physical condition.
INTELLIGENT ALL-WHEEL
DRIVE (AWD) DRIVING SAFETY
PRECAUTIONS (AWD models)
WARNING
.
Do not drive beyond the performance
capability of the tires, even with
Intelligent AWD engaged. Accelerat-
ing quickly, sharp steering maneuvers
or sudden braking may cause loss of
control.
. Always use tires of the same type,
size, brand, construction (bias, bias-

5-124Starting and driving
If any malfunction occurs in the Intelligent
All-Wheel Drive (AWD) system while the
engine is running, warning messages appear
in the vehicle information display.
JVS0228M
If the “AWD Error” warningappears, there
may be a malfunction in the Intelligent AWD
system. Reduce vehicle speed and have the
system checked as soon as possible. It is
recommended you visit an INFINITI retailer
for this service.
The “AWD High Temp.” (high temperature)
warning
may appear while trying to free a stuck vehicle due to increased oil tempera-
ture. The driving mode may change to Two-
Wheel Drive (2WD). If this warning is
displayed, stop the vehicle with the engine
idling, as soon as it is safe to do so. Then if
the warning turns off, you can continue
driving.
The “Tire Size Incorrect” warning
may
appear if there is a large difference between
the diameters of front and rear wheels. 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 any warning message continues to be
displayed, have your vehicle checked as soon
as possible. It is recommended you visit an
INFINITI retailer for this service.
WARNING
. For AWD equipped vehicles, do not
attempt 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 vehicle damage or personal
injury.
INTELLIGENT ALL-WHEEL
DRIVE (AWD) (if so equipped)

an INFINITI retailer for this service.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
driver’s responsibility to stay alert, drive
safely and be in control of the vehicle at
all times.
ANTI-LOCK BRAKING SYSTEM
(ABS)
WARNING
. The Anti-lock Braking System (ABS)
is a sophisticated device, but it
cannot prevent accidents resulting
from careless or dangerous driving
techniques. It can help maintain ve-
hicle control during braking on slip-
pery surfaces. Remember that
stopping distances on slippery sur- faces will be longer than on normal
surfaces even with ABS. Stopping
distances 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 specified size of tires on all four
wheels.
— When installing a spare tire, make sure that it is the proper size and
type as specified on the Tire and
Loading Information label. See
“Tire and loading information la-
bel” (P.10-16) of this manual.
— For detailed information, see “Wheels and tires” (P.8-32) of
this manual.
The Anti-lock Braking System (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
Starting and driving5-131
BRAKE ASSIST

automatically stopping during the same
journey.
. Whenever the Idling Stop System is
deactivated the indicator light
on the
Idling Stop OFF switch illuminates. In
this condition the Idling Stop System
cannot prevent unnecessary fuel con-
sumption, exhaust emissions, or noise
during your journey.
. If the Idling Stop System is malfunction-
ing, the indicator light
on the Idling
Stop OFF switch illuminates.
NOTE:
The Idling Stop System ON or OFF message
is displayed for a few seconds in the vehicle
information display when the Idling Stop
OFF switch is pushed. See “Idling Stop
System ON or OFF” (P.5-139).
FREEING A FROZEN DOOR LOCK
To prevent a door lock from freezing, apply
deicer through the key hole. If the lock
becomes frozen, heat the key before insert-
ing it into the key hole or use the Intelligent
Key system.
ANTIFREEZE
In the winter when it is anticipated that the
outside temperature will drop below 32°F
(0°C), check antifreeze to assure proper
winter protection. For additional informa-
tion, see “Engine cooling system (for
VR30DDTT engine models)” (P.8-6), “En-
gine cooling system (for 2.0L turbo gasoline
engine models)” (P.8-8) or “Intercooler cool-
ing system (for VR30DDTT engine models)”
(P.8-9).
BATTERY
If the battery is not fully charged during
extremely cold weather conditions, the bat-
tery fluid may freeze and damage the
battery. To maintain maximum efficiency,
the battery should be checked regularly. For
additional information, see “Battery” (P.8-
16).
DRAINING OF COOLANT WATER
If the vehicle is to be left outside without
antifreeze, drain the cooling system, includ-
ing the engine block. Refill before operating
the vehicle. For details, see “Engine cooling
system (for VR30DDTT engine models)”
(P.8-6) or “Engine cooling system (for 2.0L
turbo gasoline engine models)” (P.8-8).
TIRE EQUIPMENT
SUMMER tires have a tread designed to
provide superior performance on dry pave-
ment. 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 you consult an INFINITI re-
tailer for the tire type, size, speed rating and
availability information.
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.
Tire chains may be used. For details, see
“Tire chains” (P.8-40) of this manual.
Starting and driving5-141
COLD WEATHER DRIVING

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.