
5177-3. Do-it-yourself maintenance
7
Maintenance and care
NX300h_U_OM78007U Your vehicle is equipped with a tire pressure warning system that uses tire pres-
sure warning valves and transmitters to detect low tire inflation pressure before
serious problems arise. ●
If the tire pressure drops below a predet ermined level, the driver is warned by
a warning light. ( P. 5 6 7 )
◆ Installing tire pressure warning valves and transmitters
When replacing tires or wheels, tire pressure warning valves and transmitters
must also be installed.
When new tire pressure warning valves and transmitters are installed, new ID
codes must be registered in the tire pressure warning computer and the tire
pressure warning system must be initialized. Have tire pressure warning valve
and transmitter ID codes registered by your Lexus dealer. ( P. 5 1 9 )
◆ Initializing the tire pressure warning system ■
The tire pressure warning system must be initialized in the following circum-
stances: ●
When changing the tire inflation pressure ●
When the tire inflation pressure is changed such as when changing travel-
ing speed or load weight. ●
When rotating the tires ●
When changing the tire.
When the tire pressure warning system is initialized, the current tire inflation
pressure is set as the benchmark pressure.Tire pressure warning system ●
The tire pressure detected by the tire
pressure warning system can be dis-
played on the multi-information display.

520 7-3. Do-it-yourself maintenance
NX300h_U_OM78007U ■
Maximum load of tire
Check that the maximum load of the replacem ent tire is greater than 1 /2 of the Gross
Axle Weight Ratings (GAWR) of either the front axle or the rear axle, whichever is
greater.
■
Tire types ●
Summer tires
Summer tires are high-speed performance tires best suited to highway driving under
dry conditions. Since summer tires do not have the same traction performance as
snow tires, summer tires are inadequate for driving on snow-covered or icy roads. For
driving on snow-covered roads or icy roads, the use of snow tires is recommended.
When installing snow tires, be sure to replace all four tires. ●
All season tires
All season tires are designed to provide better traction in snow and to be adequate for
driving in most winter condit ions as well as for use year-round. All season tires, how-
ever, do not have adequate traction performance compared with snow tires in heavy
or loose snow. Also, all season tires fall short in acceleration and handling perfor-
mance compared with summer tires in highway driving. ●
Snow tires
For driving on snow-covered roads or icy roads, we recommend using snow tires. If
you need snow tires, select tires of the same size, construction and load capacity as the
originally installed tires. Since your vehicle has radial tires as original equipment, make
sure your snow tires also have radial cons truction. Do not install studded tires without
first checking local regulations for possible re strictions. Snow tires should be installed
on all wheels. ( P. 3 2 6 )■
Initializing the tire pressure warning system
Initialize the system with the tire inflation pressure adjusted to the specified level. ■
If the tread on snow tires wears down below 0.16 in. (4 mm)
The effectiveness of the tires as snow tires is lost.For the GAWR, see the Certification Label. For
the maximum load of the tire, see the load limit
at maximum cold tire inflation pressure men-
tioned on the sidewall of the tire. ( P. 6 2 1 )

5277-3. Do-it-yourself maintenance
7
Maintenance and care
NX300h_U_OM78007U ■
Instructions for checking tire inflation pressure
When checking tire inflation pressure, observe the following: ●
Check only when the tires are cold.
If your vehicle has been parked for at least 3 hours or has not been driven for more than
1 mile or 1.5 km, you will get an accurate cold tire inflation pressure reading. ●
Always use a tire pressure gauge.
It is difficult to judge if a tire is pro perly inflated based only on its appearance.●
It is normal for the tire inflation pressure to be higher after driving as heat is generated
in the tire. Do not reduce tire inflation pressure after driving. ●
Never exceed the vehicle capacity weight.
Passengers and luggage weight should be placed so that the vehicle is balanced.
WA R N I N G ■
Proper inflation is critical to save tire performance
Keep your tires properly inflated.
If the tires are not properly inflated, the following conditions may occur which could
lead to an accident resulting in death or serious injury: ●
Excessive wear ●
Uneven wear ●
Poor handling ●
Possibility of blowouts result ing from overheated tires●
Air leaking from between tire and wheel ●
Wheel deformation and/or tire damage ●
Greater possibility of tire damage while driving (due to road hazards, expansion
joints, sharp edges in the road, etc.)
NOTICE ■
When inspecting and adjust ing tire inflation pressure
Be sure to put the tire valve caps back on.
If a valve cap is not installed, dirt or moisture may get into the valve and cause an air
leak, resulting in decreased tire inflation pressure.

528 7-3. Do-it-yourself maintenance
NX300h_U_OM78007UWheels When replacing wheels, care should be taken to ensure that they are equivalent
to those removed in load capacity , diameter, rim width and inset
* .
Replacement wheels are available at your Lexus dealer.
* : Conventionally referred to as “offset”.
Lexus does not recommend using the following: ●
Wheels of different sizes or types ●
Used wheels ●
Bent wheels that have been straightened ●
Use only Lexus wheel nuts and wrenches designed for use with your alumi-
num wheels. ●
When rotating, repairing or changing your tires, check that the wheel nuts are
still tight after driving 1000 miles (1600 km). ●
Be careful not to damage the aluminum wheels when using tire chains. ●
Use only Lexus genuine balance weights or equivalent and a plastic or rubber
hammer when balancing your wheels. ■
When replacing wheels
The wheels of your vehicle are equipped with tire pressure warning valves and transmit-
ters that allow the tire pressure warning system to provide advance warning in the event
of a loss in tire inflation pressure. Whenever wheels are replaced, tire pressure warning
valves and transmitters must be installed. ( P. 5 1 7 , 5 2 9 )If a wheel is bent, cracked or heavily corroded, it should be replaced. Other-
wise, the tire may separate from the whee l or cause a loss of handling control.
Wheel selection
Aluminum wheel precautions

608 9-1. Specifications
NX300h_U_OM78007UMaintenance data (fuel, oil level, etc.)
* 1
: Unladen vehicle
* 2
: Vehicles with towing packageDimensions and weight Overall length 182.3 in. (4630 mm)
Overall width 72.6 in. (1845 mm)
Overall height
* 1
64.8 in. (1645 mm)
Wheelbase 104.7 in. (2660 mm)
Tr e a d Front 62.2 in. (1580 mm)
Rear 62.2 in. (1580 mm)
Vehicle capacity weight
(Occupants + luggage) 895 lb. (405 kg)
Trailer Weight Rating
* 2
(Trailer weight + cargo weight) 1500 lb. (685 kg)

6279-1. Specifications
9
Vehicle specifications
NX300h_U_OM78007U Glossary of tire terminology Tire related term Meaning
Cold tire inflation pressure Tire pressure when the vehicle has been parked for
three hours or more, or has not been driven more than 1
mile or 1.5 km un der that condition
Maximum inflation pres-
sure The maximum cold inflated pressure to which a tire may
be inflated, shown on the sidewall of the tire
Recommended inflation
pressure Cold tire inflation pressure recommended by a manu-
facturer
Accessory weight The combined weight (in excess of those standard items
which may be replaced) of transmission, power steer-
ing, power brakes, power wi ndows, power seats, radio
and heater, to the extent that these items are available as
factory-installed equipment (whether installed or not)
Curb weight The weight of a motor vehicle with standard equipment,
including the maximum capacity of fuel, oil and coolant,
and if so equipped, air co nditioning and additional
weight optional engine
Maximum loaded vehicle
weight The sum of:
(a) Curb weight
(b) Accessory weight
(c) Vehicle capacity weight
(d) Production options weight
Normal occupant weight 150 lb. (68 kg) times the numb er of occupa nts specified
in the second column of Table 1
* that follows
Occupant distribution Distribution of occupants in a vehicle as specified in the
third column of Table 1
* below

628 9-1. Specifications
NX300h_U_OM78007U Production options weight The combined weight of installed regular production
options weighing over 5 lb. (2.3 kg) in excess of the
standard items which they replace, not previously con-
sidered in curb weight or accessory weight, including
heavy duty brakes, ride levelers, roof rack, heavy duty
12-volt battery, and special trim
Rim A metal support for a tire or a tire and tube assembly
upon which the tire beads are seated
Rim diameter
(Wheel diameter) Nominal diameter of the bead seat
Rim size designation Rim diameter and width
Rim type designation The industry manufacturer’s designation for a rim by
style or code
Rim width Nominal distance between rim flanges
Vehicle capacity weight
(Total load capacity) The rated cargo and luggage load plus 150 lb. (68 kg)
times the vehicle’s designated seating capacity
Vehicle maximum load on
the tire The load on an individual tire that is determined by dis-
tributing to each axle its share of the maximum loaded
vehicle weight, and dividing by two
Vehicle normal load on the
tire The load on an individual tire that is determined by dis-
tributing to each axle its sh are of curb weight, accessory
weight, and normal occupant weight (distributed in
accordance with Table 1
* below), and dividing by two
We a t h e r s i d e The surface area of the rim not covered by the inflated
tire
Bead The part of the tire that is made of steel wires, wrapped
or reinforced by ply cords and that is shaped to fit the
rimTire related term Meaning

630 9-1. Specifications
NX300h_U_OM78007U Intended outboard sidewall (a) The sidewall that contains a whitewall, bears white
lettering, or bears manufacturer, brand, and/or
model name molding that is higher or deeper than
the same molding on the other sidewall of the tire, or
(b) The outward facing sidewall of an asymmetrical tire
that has a particular side that must always face out-
ward when mounted on a vehicle
Light truck (LT) tire A tire designated by its manufacturer as primarily
intended for use on lightweight trucks or multipurpose
passenger vehicles
Load rating The maximum load that a tire is rated to carry for a given
inflation pressure
Maximum load rating The load rating for a tire at the maximum permissible
inflation pressure for that tire
Maximum permissible infla-
tion pressure The maximum cold inflation pressure to which a tire may
be inflated
Measuring rim The rim on which a tire is fitted for physical dimension
requirements
Open splice Any parting at any junction of tread, sidewall, or inner-
liner that extends to cord material
Outer diameter The overall diameter of an inflated new tire
Overall width The linear distance between the exteriors of the side-
walls of an inflated tire, incl uding elevations due to label-
ing, decorations, or pr otective bands or ribs
Passenger car tire A tire intended for use on passenger cars, multipurpose
passenger vehicles, and trucks, that have a gross vehicle
weight rating (GVWR) of 10,000 lb. or less.
Ply A layer of rubber-coated parallel cords
Ply separation A parting of rubber compou nd between adjacent pliesTire related term Meaning