2015 Lexus GS450h tires

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4-5. Using the driving support systems
■Reduced effectiveness of the EPS system
The effectiveness of the EPS system is reduced to prevent the system from overheat-
ing when there is frequent steering input over an extended period of time. The steer-
ing wheel may feel heavy as a result.
* Should this occur, refrain from excessive
steering input or stop the vehicle and turn the hybrid system off. The EPS system
should return to normal within 10 minutes.
*: If the LKA (Lane-Keeping Assist) system cannot operate in this case, a warning
message will be shown on the multi-information display.
CAUTION
■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 roads.
■Stopping distance when the ABS is operating may exceed that of normal condi-
tions
The ABS is not designed to shorten the vehicle’s stopping distance. Always main-
tain a safe distance from the vehicle in front of you, especially in the following situa-
tions:
●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 driving on slippery
road surfaces, even if the TRAC system is operating.
Drive the vehicle carefully in conditions where stability and power may be lost.
■When the VSC is 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 systems are turned off
Be especially careful and drive at a speed appropriate to the road conditions. As
these are the systems to help ensure vehicl e stability and driving force, do not turn
the TRAC/VSC systems off unless necessary.
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2894-5. Using the driving support systems
4
Driving
CAUTION
■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
inflation 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 modifying the suspension will affect the
driving assist systems, and may cause a system to malfunction.
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3174-6. Driving tips
4
Driving
◆Air conditioning
Use the air conditioning only when necessary. Doing so can help con-
trol excessive gasoline consumption.
In summer: In high temperatures, use the recirculated air mode. Doing
so will help to reduce the burden on the air conditioner and reduce fuel
consumption as well.
In winter: Because the gasoline engine will not automatically cut out
until the gasoline engine and the interior of the vehicle are warm, it will
consume fuel. Also, fuel consumption can be improved by avoiding
overuse of the heater.
◆Checking tire inflation pressure
Make sure to check the tire inflation pressure frequently. Improper tire
inflation pressure can cause poor fuel consumption.
Also, as snow tires can cause large amounts of friction, their use on dry
roads can lead to poor fuel consumption. Use a tire that is appropriate
for the season.
◆Luggage
Carrying heavy luggage can lead to poor fuel consumption. Avoid car-
rying unnecessary luggage. Installing a large roof rack can also cause
poor fuel consumption.
◆Warming up before driving
Since the gasoline engine starts up and cuts out automatically when
cold, warming up the engine is unnecessary. Moreover, frequently driv-
ing short distances will cause the engine to repeatedly warm up, which
can lead to poor fuel consumption.
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4-6. Driving tips
Winter 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 rear tires.
*
Ensure that all tires are the specified size and brand, and that chains match the
size of the tires.
*: Tire chains cannot be mounted on vehicles with front and rear tires of differing
sizes and vehicles with LDH and 19-inch tires.
Carry out the necessary preparatio ns and inspections before driving
the vehicle in winter. Always drive the vehicle in a manner appropriate
to the prevailing weather conditions.
Preparation for winter
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3194-6. Driving tips
4
Driving
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 immediately 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 wind-
shield.
●Check for and remove any excess ice or snow that may have accumu-
lated 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.
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 without setting the parking
brake. The parking brake may freeze up, preventing it from being
released. If necessary, block the wheels to prevent inadvertent sliding or
creeping.
Before driving the vehicle
When driving the vehicle
When parking the vehicle
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4-6. Driving tips
XVehicles with front and rear tires of the same size except for the vehi-
cles with LDH and 19 inch tires
Use the correct tire chain size wh en mounting the tire chains.
Chain size is regulated for each tire size.
Side chain
(0.12 in. [3 mm] in diameter)
Cross chain
(0.16 in. [4 mm] in diameter)
XVehicles with front and rear tires of differing sizes and vehicles with
LDH and 19 inch tires
Tire chains cannot be mounted.
Snow tires should be used instead.
Regulations regarding the use of tire chains vary depending on location
and type of road. Always check loca l regulations before installing chains.
Selecting tire chains
1
2
Regulations on the use of tire chains
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3214-6. Driving tips
4
Driving
If heavy snow or icy condition is expected, shift the rest position manually.
Grip the hook section of the wiper arm firmly when shifting the wiper
position.
■To rest position
Raise the wiper in line with the
windshield.
You can stand the wipers up for the
rest position.
★ : More than 3.9 in. (10 cm)
■To retract position
Lower the wipers by pressing on
the upper part of the hook sec-
tion.
■Tire chain installation
Observe the following precautions when installing and removing chains:
●Install and remove tire chains in a safe location.
●Install tire chains on the rear tires. Do not install tire chains on the front tires.
●Install tire chains on rear tires as tightly as possible. Retighten chains after driving
1/4  1/2 mile (0.5  1.0 km).
●Install tire chains following the instructions provided with the tire chains.
Shifting the windshield wiper position
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4-6. Driving tips
CAUTION
■Driving with snow tires
Observe the following precautions to reduce the risk of accidents.
Failure to do so may result in a loss of vehicle 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.
●Do not use LKA (Lane-Keeping Assist) system.
■Driving with tire chains (vehicles with front and rear tires of the same size except
for the vehicles with LDH and 19 inch tires)
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, abrupt steering, sudden braking and shifting opera-
tions that cause sudden engine braking.
●Slow down sufficiently before entering a curve to ensure that vehicle control is
maintained.
●Do not use LKA (Lane-Keeping Assist) system.
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