tires LEXUS NX300h 2015 User Guide

218 4-2. Driving procedures
NX300h_U_OM78007UASC (Active Sound Control) 
Louder
Lower The indicator comes on when the ASC
system is on.
When the dial is turned to the lowest
volume, the ASC system will be turned
off and the indicator will go off. ■
The ASC system can be operated when
The driving mode select switch is in normal mode or sport mode.■
Temporary cancelation of the ASC system functions
The ASC system may be temporarily cancele d depending on the driving conditions,
such as when the tires slip due to sudden acceleration.
 : If equippedThe ASC system is an electronic sound system that generates engine sound,
conveying the kinetic situations of the vehicle’s accelerati on and deceleration
to the driver through the speake rs inside the instrument panel.
The vehicle’s response to the driver’s acceleration behavior and shift opera-
tions are also conveyed in sound.
When sport mode is selected, the sound co nveyed to the driver will be louder.
Controlling volume 1
2

276 4-5. Using the driving support systems
NX300h_U_OM78007U ●
When the lane markers are on a curb, etc. ●
When driving on a particularly brig ht road surface, such as concrete●
When driving on a road surface that is bright due to reflected light ●
When driving in a location wh ere the light level changes rapi dly, such as the entrance to
or exit from a tunnel ●
When sunlight or the headlights of oncoming vehicles are shining directly into the cam-
era lens ●
When driving on roads that are branching or merging ●
When driving on a hill ●
When driving on winding roads or roads that are uneven ●
When driving on rough or unpaved roads ●
When driving on a sharp curve ●
When lane markers are extremely narrow or extremely wide ●
When the vehicle leans to one side an unus ual amount due to a heavy load or improper
tire inflation pressure ●
When the following distance between your vehicle and the vehicle ahead is extremely
short ●
When the vehicle experiences strong up-and -down motion such as when driving on an
extremely rough road or on a seam in the pavement ●
When headlight brightness at nighttime is reduced due to dirt on the lenses, or when
the headlights are misaligned ●
When receiving a side wind ■
When changing the tires
Depending on the tires used, sufficient performance may not be maintainable.■
Warning messages for the LDA
Warning messages are used to indicate a syst em malfunction or to inform the driver of
the need for caution while driving. If a wa rning message is shown on the multi-informa-
tion display, read the message and follow the instructions.
Also, even if a warning message is displayed, it will not impede normal driving. ■
When turning on/off the steering control function
From “Settings display” (  P. 103) of the multi-information display, the steering
control function can be turned on/off.
Pressing the or meter control switches (  P. 103), selects
With each press of meter control switch es, the control switches between “On” and
“Off” ■
Sensitivity adjustment for th e lane deviation alert buzzer
From
“Settings display” (  P. 103) of the multi-inform ation display, the alert sen-
sitivity for the alert buzzer when deviating from the lane can be adjusted.
Pressing the or meter control switches (  P. 103), selects
With each press of meter control switches, the control switches between “High”
and “Standard” 1
2
1
2

2774-5. Using the driving support systems
4
Driving
NX300h_U_OM78007U WA R N I N G ■
Before using the LDA
Do not over rely on the LDA. The LDA does not drive the vehicle automatically, nor
does it reduce the amount of care you need to take. As such, the driver must always
assume full responsibility for understandin g his/her surroundings, for operating the
steering wheel to correct the driving line, and for driving safely. Also, take occasional
rests from fatigue due to driving over long periods of time, etc.
Inappropriate or negligent driving co uld lead to an unexpected accident.■
Do not drive without holding the steering wheel
While the steering control function is operating, when the system judges that the vehi-
cle is being driven without holding the steering wheel, a warning message is displayed.
(  P. 2 7 1 )
Inappropriate steering wheel operations and/or negligent driving could lead to an
unexpected accident. When driving, firmly ho ld the steering wheel and keep safe driv-
ing in mind. ■
To avoid operating the LDA by mistake
Switch the LDA off using the LDA switch when not in use. (  P. 2 7 2 )■
Situations unsuitable for LDA
Do not use the LDA in any of the following situations.
Otherwise, the system may not function correctly and could result in an accident. ●
When driving with snow tires, tire ch ains, a spare tire, or similar equipment●
When a tire with a different structure, maker, brand, or tread pattern is used. ●
When remain tread of the tire or the air pressure is insufficient●
When restructuring the suspension ●
When there are objects or structures along the roadside that might be misinterpreted
as lane markers (such as guardrails, a curb, reflector posts, etc.) ●
When driving on snowy roads ●
When pavement lane markers are difficult to see due to rain, snow, fog, sand, dust,
etc. ●
When there are visible lines on the pavement from road repairs, or if the remains of
old lane markers are still visible on the road ●
When driving on a road with lane closures due to maintenance, or when driving in a
temporary lane ●
When driving on road surfaces that are slippery from rain, snow, etc.●
When driving in traffic lanes other than highways and freeway ●
When driving through construction areas

3014-5. Using the driving support systems
4
Driving
NX300h_U_OM78007U WA R N I N G ■
When using the Lexus parking assist monitor system
The parking assist monitor is a supplemental device intended to assist the driver when
backing up. When backing up, be sure to chec k visually behind and all around the vehi-
cle before proceeding.
Observe the following precautions to avoid an accident that could result in death or
serious injuries. ●
Never depend on the parking assist monitor entirely when backing up. The image
and the position of the guide lines displaye d on the screen may differ from the actual
state.
Use caution, just as you would when backing up any vehicle. ●
Be sure to back up slowly, depressing the brake pedal to control vehicle speed. ●
If you seem likely to hit nearby vehicles, obstacles, people or mount the shoulder,
depress the brake pedal to stop the vehicle. ●
The instructions given are only guidelines.
When and how much to turn the steering wheel will vary according to traffic condi-
tions, road surface conditions, vehicle condit ion, etc. when parking. It is necessary to
be fully aware of this before using the parking assist system. ●
When parking, be sure to check that the par king space will accommodate your vehi-
cle before maneuvering into it. ●
Do not use the parking assist monitor in the following cases:
• On icy or slick road surfaces, or in snow
• When using tire chains or emergency tires
• When the back door is not closed completely
• On roads that are not flat or straight, such as curves or slopes. ●
In low temperatures, the screen may darken or the image may become faint. The
image could distort when the vehicle is moving, or you may become unable to see the
image on the screen. Be sure to check dire ct visually and with the mirrors all around
the vehicle before proceeding. ●
If the tire sizes are changed, the position of the guide lines displayed on the screen
may change. ●
The camera uses a special lens. The dist ances between objects and pedestrians that
appear in the image displayed on the screen will differ from the actual distances.
(  P. 2 9 5 ) ●
Estimated course line display mode: If the st eering wheel is straight and the vehicle
width guide lines and the estimated course li nes are not in alignment, have the vehicle
inspected by your Lexus dealer.

3094-5. Using the driving support systems
4
Driving
NX300h_U_OM78007U WA R N I N G ■
The ABS does not operate effectively when ●
The limits of tire gripping performance have been exceeded (such as excessively
worn tires on a snow covered road). ●
The vehicle hydroplanes while driving at high speed on wet or slick road. ■
Stopping distance when the ABS is operat ing may exceed that of normal conditions
The ABS is not designed to shorten the vehicle’s stopping distance. Always maintain a
safe distance from the vehicle in front of you, especially in the following situations:●
When driving on dirt, gravel or snow-covered roads ●
When driving with tire chains ●
When driving over bumps in the road ●
When driving over roads with potholes or uneven surfaces ■
TRAC may not operate effectively when
Directional control and power may not be achievable while drivin g on slippery road
surfaces, even if the TRAC system is operating.
Drive the vehicle carefully in conditions where stability and power may be lost. ■
Hill-start assist control does not operate effectively when ●
Do not overly rely on the hill-start assist control. The hill-start assist control may not
operate effectively on steep inclines and roads covered with ice. ●
Unlike the parking brake, hill-start assist control is not intended to hold the vehicle
stationary for an extended period of time. Do not attempt to use hill-start assist con-
trol to hold the vehicle on an incline, as doing so may lead to an accident. ■
When the TRAC, VSC and/or ABS are activated
The slip indicator light flashes. Always drive carefully. Reckless driving may cause an
accident. Exercise particular care when the indicator light flashes. ■
When the TRAC/VSC system are turned off
Be especially careful and drive at a speed ap propriate to the road conditions. As these
are the systems to help ensure vehicle st ability and driving force, do not turn the
TRAC/VSC systems off unless necessary. ■
Replacing tires
Make sure that all tires are of the specified size, brand, tread pattern and total load
capacity. In addition, make sure that the tires are inflated to the recommended tire infla-
tion pressure level.
The ABS, TRAC and VSC systems will not function correctly if different tires are
installed on the vehicle.
Contact your Lexus dealer for further information when replacing tires or wheels. ■
Handling of tires and the suspension
Using tires with any kind of problem or modi fying the suspension will affect the driving
assist systems, and may caus e a system to malfunction.

3254-6. Driving tips
4
Driving
NX300h_U_OM78007U ◆ Delays
Repeated acceleration and deceleration, as well as long waits at traffic lights,
will lead to bad fuel economy. Check traffic reports before leaving and avoid
delays as much as possible. When drivin g in a traffic jam, gently release the
brake pedal to allow the vehicle to move forward slightly while avoiding over-
use of the accelerator pedal. Doing so can help control excessive gasoline
consumption.
◆ Highway driving
Control and maintain the vehicle at a co nstant speed. Before stopping at a toll
booth or similar, allow plenty of time to release the accelerator and gently
apply the brakes. A greater amount of electrical energy can be regenerated
when slowing down.
◆ Air conditioning
Use the air conditioning only when necessary. Doing so can help reduce
excessive gasoline consumption.
In summer: When the ambient temperature is high, use the recirculated air
mode. Doing so will help to reduce th e burden on the air conditioning system
and reduce fuel consumption as well.
In winter: Because the gasoline engine will not automatically cut out until it
and the interior of the vehicle are warm, it will consume fuel. Also, fuel con-
sumption can be improved by avoiding overuse of the heater.
◆ Checking tire inflation pressure
Make sure to check the tire inflation pressure frequently. Improper tire infla-
tion pressure can cause poor fuel economy.
Also, as snow tires can cause large amou nts of friction, their use on dry roads
can lead to poor fuel economy. Use ti res that are appropriate for the season.
◆ Luggage
Carrying heavy luggage will lead to poor fuel economy. Avoid carrying
unnecessary luggage. Installing a large roof rack will also cause poor fuel
economy.
◆ Warming up before driving
Since the gasoline engine starts up and cuts out automatically when cold,
warming up the engine is unnecessary. Moreover, frequently driving short dis-
tances will cause the engine to repeated ly warm up, which can lead to excess
fuel consumption.

326 4-6. Driving tips
NX300h_U_OM78007UWinter driving tips ●
Use fluids that are appropriate to the prevailing outside temperatures.
•Engine oil
• Engine/power control unit coolant
• Washer fluid ●
Have a service technician inspect the condition of the 12-volt battery. ●
Have the vehicle fitted with four snow tires or purchase a set of tire chains for
the front tires
* . Ensure that all tires are the same size and br and, and that chains match the size of the
tires.
* : Tire chains cannot be mounted on the 225/60R18 tires.
Perform the following according to the driving conditions: ●
Do not try to forcibly open a window or move a wiper that is frozen. Pour
warm water over the frozen area to melt the ice. Wipe away the water imme-
diately to prevent it from freezing. ●
To ensure proper operation of the climate control system fan, remove any
snow that has accumulated on the air inlet vents in front of the windshield. ●
Check for and remove any excess ice or snow that may have accumulated on
the exterior lights, vehicle’s roof, chassis, around the tires or on the brakes. ●
Remove any snow or mud from the bottom of your shoes before getting in the
vehicle.Carry out the necessary preparations and inspections before driving the vehi-
cle in winter. Always drive the vehicle in a manner appropriate to the prevail-
ing weather conditions.
Pre-winter preparations
Before driving the vehicle

3274-6. Driving tips
4
Driving
NX300h_U_OM78007U Accelerate the vehicle slowly, keep a safe distance between you and the vehicle
ahead, and drive at a reduced speed suitable to road conditions.●
Park the vehicle and move the shift lever to P and block the wheel under the
vehicle without setting the parking brake. The parking brake may freeze up,
preventing it from being released. When the parking brake is in automatic mode, release the parking brake after shifting
the shift lever to P. (  P. 2 1 3 )●
If the vehicle is left parked with the br akes damp in cold temperatures, there is
a possibility of the brakes freezing.
Use the correct tire chain size when mounting the tire chains. Chain size is regu-
lated for each tire size. 
Vehicles with 225/65R17 tires
Side chain:
3 mm (0.12 in.) in diameter
10 mm (0.39 in.) in width
25 mm (0.98 in.) in length
Cross chain:
4 mm (0.16 in.) in diameter
14 mm (0.55 in.) in width
25 mm (0.98 in.) in length 
Vehicles with 225/60R18 tires
Tire chains cannot be mounted on the 225/60R18 tires. Snow tires should be
use instead.
Regulations regarding the use of tire chains vary depending on location and type
of road. Always check local regulations before installing chains.When driving the vehicle
When parking the vehicle
Selecting tire chains 1
2
3
4
5
6
Regulations on the use of tire chains

328 4-6. Driving tips
NX300h_U_OM78007U ■
Tire chain installation
Observe the following precautions wh en installing and removing chains:●
Install and remove tire chains in a safe location. ●
Install tire chains on the front tires only. Do not install tire chains on the rear tires. ●
Install tire chains on front tires as tightl y as possible. Retighten chains after driving
1/4 -1/2 mile (0.5 - 1.0 km). ●
Install tire chains following the instru ctions provided with the tire chains.
WA R N I N G ■
Driving with snow tires
Observe the following precautions to reduce the risk of accidents.
Failure to do so may result in a loss of ve hicle control and cause death or serious injury.●
Use tires of the specified size. ●
Maintain the recommended level of air pressure. ●
Do not drive in excess of 75 mph (120 km/h), regardless of the type of snow tires
being used. ●
Use snow tires on all, not just some wheels.■
Driving with tire chains
Observe the following precautions to reduce the risk of accidents.
Failure to do so may result in the vehicle being unable to be driven safely, and may
cause death or serious injury. ●
Do not drive in excess of the speed limit specified for the tire chains being used, or
30 mph (50 km/h), whichever is lower. ●
Avoid driving on bumpy road surfaces or over potholes. ●
Avoid sudden acceleration, ab rupt steering, sudden bra king and shifting operations
that cause sudden engine braking. ●
Slow down sufficiently before entering a cu rve to ensure that vehicle control is main-
tained. ●
Do not use LDA (Lane Departure Alert with steering control) (if equipped). ■
When parking the vehicle
When parking the vehicle without applying the parking brake, make sure to chock the
wheels. If you do not chock the wheels, the vehicle may move unexpectedly, possibly
resulting in an accident.

3294-6. Driving tips
4
Driving
NX300h_U_OM78007U NOTICE ■
Repairing or replacing snow tires
Request repairs or replacement of snow tires from Lexus dealers or legitimate tire
retailers.
This is because the removal and attachment of snow tires affects the operation of the
tire pressure warning valves and transmitters. ■
Fitting tire chains
The tire pressure warning valves and transmitters may not function correctly when tire
chains are fitted.