SUBARU IMPREZA WRX 2007 3.G Owners Manual

For U.S.A............................................................ 13-2
Tire information .................................................. 13-2
Tire labeling ....................................................... 13-2
Recommended tire inflation pressure .................. 13-5
Glossary of tire terminology ............................... 13-6
Tire care –maintenance and safety practices ...... 13-7
Vehicle load limit –how to determine .................. 13-8
Determining compatibility of tire and vehicle load capacities ...................................................... 13-10 Adverse safety consequences of overloading on
handling and stopping and on tires ................ 13-11
Steps for Determining Correct Load Limit ......... 13-11
Uniform tire quality grading standards .......... 13-12
Treadwear ....................................................... 13-12
Traction AA, A, B, C ......................................... 13-12
Temperature A, B, C ......................................... 13-12
Reporting safety defects (USA) ...................... 13-13
Consumer information and Reporting safety defects
13

13-2Consumer information and Reporting safety defects
For U.S.A.
The following information has been
compiled according to Code of Fed-
eral Regulations “Title 49, Part 575 ”. Tire information &
Tire labeling
Many markings (e.g. Tire size, Tire
Identification Number or TIN) are
placed on the sidewall of a tire by tire
manufacturers. These markings can
provide you with useful information on
the tire. ! Tire size
Your vehicle comes equipped with P-
Metric tire size. It is important to
understand the sizing system in se-
lecting the proper tire for your vehi-
cles. Here is a brief review of the tire
sizing system with a breakdown of its
individual elements. ! P Metric
With the P-Metric system, Section
Width is measured in millimeters. To
convert millimeters into inches, divide
by 25.4. The Aspect Ratio (Section
Height divided by Section Width)
helps provide more dimensional in-
formation about the tire size. Example:
(1) P = Certain tire type used on
light duty vehicles such as passenger
cars
(2) Section Width in millimeters
(3) Aspect Ratio (= section height
7
section width).
(4) R = Radial Construction
(5) Rim diameter in inches ! Load and Speed Rating Descrip- tions
The load and speed rating descrip-
tions will appear following the size
designation.
They provide two important facts
about the tire. First, the number
designation is its load index. Second,
the letter designation indicates thetire ’s speed rating.

Example:
(6) Load Index: A numerical code
which specifies the maximum load a
tire can carry at the speed indicated
by its speed symbol, at maximum
inflation pressure.
For example,“90 ”means 1,323 lbs
(600 kg), “89 ”means 1,278 lbs (580
kg).
WARNING
Load indices apply only to the
tire, not to the vehicle. Putting a
load rated tire on any vehicle
does not mean the vehicle can
be loaded up to the tire ’s rated
load.
(7) Speed Rating: An alphabetical
system describing a tire ’s capability to
travel at established and predeter-
mined speeds.
For example, “V ” means 149 mph
(240 km/h)
WARNING
. Speed ratings apply only to
the tire, not to the vehicle.
Putting a speed rated tire on
any vehicle does not mean
the vehicle can be operated at
the tire ’s rated speed.
. The speed rating is void if the
tires are worn out, damaged,
repaired, retreaded, or other-
wise altered from their origi-
nal condition. If tires are re-
paired, retreaded, or other-
wise altered, they may not be
suitable for original equip-
ment tire designed loads and speeds.
! Tire Identification Number (TIN)
Tire Identification Number (TIN) is
marked on the intended outboard
sidewall. The TIN is composed of four
groups. Here is a brief review of the
TIN with a breakdown of its individual
elements.(1) Manufacturer ’s Identification
Mark
(2) Tire Size
(3) Tire Type Code
(4) Date of Manufacture
The first two figures identify the week,
starting with “01 ”to represent the first
full week of the calendar year; the
second two figures represent the
year. For example, 0101 means the
1st week of 2001. ! Other markings
The following makings are also
placed on the sidewall. ! Maximum permissible inflation
pressure
The maximum cold inflation pressure
to which this tire may be inflated. For
example, “300 kPa (44 PSI) MAX.
PRESS ”
! Maximum load rating
Theloadratingatthemaximum
permissible weight load for this tire.
For example, “MAX. LOAD 580 kg
(1279 LBS) @ 300 kPa (44 PSI) MAX.
PRESS. ”
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13-4Consumer information and Reporting safety defects
WARNING
Maximum load rating applies
only to the tire, not to the
vehicle. Putting a load rated tire
on any vehicle does not mean
the vehicle can be loaded up to
the tire ’s rated load.
! Construction type
Applicable construction of this tire.
For example, “TUBELESS STEEL
BELTED RADIAL ”
! Construction
The generic name of each cord
material used in the plies (both side-
wall and tread area) of this tire.
For example, “PLIES: TREAD 2
STEEL + 2 POLYESTER SIDEWALL
2 POLYESTER ”
! Uniform Tire Quality Grading
(UTQG)
For details, refer to “Uniform tire
quality grading standards ”in this
chapter.

&Recommended tire inflation pressure
! Recommended cold tire inflation pressure
Recommended cold tire inflation pressure for your vehicle ’s tires is as follows,
Tire size P205/55R16 89V 215/45R17 91W 225/45R17 90W
Wheel size 16 66
1/2JJ 17 67JJ 17 68JJ
Pressure Front 33 psi (230 kPa, 2.3 kgf/cm
2) 33 psi (230 kPa, 2.3 kgf/cm2) 35 psi (240 kPa, 2.4 kgf/cm2)
Rear 30 psi (210 kPa, 2.1 kgf/cm
2) 32 psi (220 kPa, 2.2 kgf/cm2) 29 psi (200 kPa, 2.0 kgf/cm2)
Temporary
spare tire Size T135/70 D16 T135/70 D17 Pressure
60 psi (420 kPa, 4.2 kgf/cm
2)
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13-6Consumer information and Reporting safety defects
! Vehicle placard
The vehicle placard is affixed to the driver ’s side B-pillar.
Example:
The vehicle placard shows original
tire size, recommended cold tire infla-
tion pressure on each tire at max-
imum loaded vehicle weight, seating
capacity and loading information. ! Adverse safety consequences
of under-inflation
Driving at high speeds with exces-
sively low tire pressures can cause
the tires to flex severely and to rapidly
become hot. A sharp increase in
temperature could cause tread se-
paration, and failure of the tire(s).
Possible resulting loss of vehicle
control could lead to an accident. ! Measuring and adjusting air
pressure to achieve proper in-
flation
Check and, if necessary, adjust the
pressure of each tire (including the
spare) at least once a month and
before any long journey. Check the
tire pressures when the tires are cold.
Use a pressure gauge to adjust the
tire pressures to the specific values.
Driving even a short distance warms
up the tires and increases the tire
pressures. Also, the tire pressures are affected by the outside temperature. It
is best to check tire pressure outdoors
before driving the vehicle. When a tire
becomes warm, the air inside it
expands, causing the tire pressure to
increase. Be careful not to mistakenly
release air from a warm tire to reduce
its pressure. &
Glossary of tire terminology
. Cold tire pressure
The pressure in a tire that has been
driven less than 1 mile or has been
standing for three hours or more. . Maximum inflation pressure
The maximum cold inflation pressure
to which a tire may be inflated. . Recommended inflation pres-
sure
The cold inflation pressure recom-
mended by a vehicle manufacturer. . Intended outboard sidewall
(1) 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 (2) The outward facing sidewall of

an asymmetrical tire that has a
particular side that must always
face outward when mounting on a
vehicle.
. Accessory weight
The combined weight (in excess of
those standard items which may be
replaced) of floor mats, leather seats
and cross bars to the extent that these
items are available as factory-in-
stalled 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 air conditioning. . Maximum loaded vehicle weight
The sum of curb weight, accessory
weight, vehicle capacity weight and
production options weight. . Normal occupant weight
150 lbs (68 kg) times the number of
occupants (3 occupants). . Occupant distribution
Distribution of occupants in a vehicle,
2 in front, 1 in rear seat. .
Production options weight
The combined weight of those in-
stalled regular production options
weighing over 5.1 lbs (2.3 kg) in
excess of those standards items
which they replace, not previously
considered in curb weight or acces-
sory weight. . Vehicle capacity weight
The total weight of cargo, luggage
and occupants that can be added to
the vehicle. . Vehicle maximum load on a tire
Load on an individual tire that is
determined by distributing to each
axle its share of the maximum loaded
vehicle weight and dividing by two. . Vehicle normal load on a tire
Load on an individual tire that is
determined by distributing to each
axle its share of the curb weight,
accessory weight, and normal occu-
pant weight and dividing by two. & Tire care –maintenance and
safety practices
. Check on a daily basis that the tires
are free from serious damage, nails,
and stones. At the same time, check the tires for abnormal wear. .
Inspect the tire tread regularly and
replace the tires before their tread
wear indicators become visible. When
a tire ’s tread wear indicator becomes
visible, the tire is worn beyond the
acceptable limit and must be replaced
immediately. With a tire in this condi-
tion, driving at even low speeds in wet
weather can cause the vehicle to
hydroplane. Possible resulting loss
of vehicle control can lead to an
accident. . To maximize the life of each tire
and ensure that the tires wear uni-
formly, it is best to rotate the tires
every 7,500 miles (12,500 km). Rotat-
ing the tires involves switching the
front and rear tires on the right-hand
side of the vehicle and similarly
switching the front and rear tires on
the left-hand side of the vehicle.
(Each tire must be kept on its original
side of the vehicle.) Replace any
damaged or unevenly worn tires at
the time of rotation. After tire rotation,
adjust the tire pressures and make
sure the wheel nuts are correctly
tightened. A tightening torque specifi-
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13-8Consumer information and Reporting safety defects
cation and a tightening sequence
specification for the wheel nuts can
be found “Flat tires ”section in chapter
9. & Vehicle load limit –how to
determine
The load capacity of your vehicle is
determined by weight, not by avail-
able cargo space. The load limit of
your vehicle is shown on the vehicle
placard attached to the driver ’s side
B-pillar. Locate the statement “The
combined weight of occupants and
cargo should never exceed XXX kg or
XXX lbs ”on your vehicle ’s placard.
The vehicle placard also shows seat-
ing capacity of your vehicle.
The total load capacity includes the
total weight of driver and all passen-
gers and their belongings, any cargo,
any optional equipment such as a
trailer hitch, roof rack or bike carrier,
etc., and the tongue load of a trailer.
Therefore cargo capacity can be
calculated by the following method.
Cargo capacity = Load limit (total
weight of occupants + total weight of optional equipment + tongue load of a
trailer (if applicable))
For towing capacity information and
weight limits, refer to
“Trailer towing ”
section in chapter 8. ! Calculating total and load ca-
pacities varying seating con-
figurations
Calculate the available load capacity
as shown in the following examples:
Example 1A
Vehicle capacity weight of the vehicle
is 900 lbs (408 kg), which is indicated
on the vehicle placard with the state-ment “The combined weight of occu-
pants and cargo should never exceed 900 lbs or 408 kg
”.
For example, if the vehicle has one
occupant weighing 154 lbs (70 kg)
plus cargo weighing 662 lbs (300 kg).
1. Calculate the total weight.
2. Calculate the available load capa-
city by subtracting the total weight
from the vehicle capacity weight of
900 lbs (408 kg).
3. The result of step 2 shows that a
further 84 lbs (38 kg) of cargo can be
carried.

Example 1B
For example, if a person weighing 176
lbs (80 kg) now enters the same
vehicle (bringing the number of occu-
pants to two), the calculations are as
follows:
1. Calculate the total weight.
2. Calculate the available load capa-
city.
3. The total weight now exceeds the
capacity weight by 92 lbs (42 kg), so
the cargo weight must be reduced by
92 lbs (42 kg) or more.
Example 2A
Vehicle capacity weight of the vehicle
is 900 lbs (408 kg), which is indicated
on the vehicle placard with the state-ment
“The combined weight of occu-
pants and cargo should never exceed
408 kg or 900 lbs ”.
For example, the vehicle has one
occupant weighing 165 lbs (75 kg)
plus cargo weighing 375 lbs (170 kg).
In addition, the vehicle is fitted with a
trailer hitch weighing 22 lbs (10 kg), to
which is attached a trailer weighing
1,764 lbs (800 kg). 10% of the trailer
weight is applied to the trailer tongue
(i.e. Tongue load = 176 lbs (80 kg)).
1. Calculate the total weight.
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13-10Consumer information and Reporting safety defects
2. Calculate the available load capa-
city.
3. The result of step 2 shows that a
further 162 lbs (73 kg) of cargo can be
carried.
Example 2B
For example, if a person weighing 143
lbs (65 kg) and a child weighing 40 lbs
(18 kg) now enter the same vehicle
(bringing the number of occupants to three), and a child restraint system
weighing 11 lbs (5 kg) is installed in
the vehicle for the child to use, the
calculations are as follows:
1. Calculate the total weight.
2. Calculate the available load capa-
city.
3. The total weight now exceeds the
capacity weight by 32 lbs (15 kg), so
the cargo weight must be reduced by
32 lbs (15 kg) or more. &
Determining compatibility of
tire and vehicle load capaci- ties
The sum of four tires ’maximum load
ratings must exceed the maximum
loaded vehicle weight ( “GVWR ”). In
addition, sum of the maximum load
ratings of two front tires and of two
rear tires must exceed each axle ’s
maximum loaded capacity ( “GAWR ”).
Original equipment tires are designed
to fulfill those conditions.
The maximum loaded vehicle weight
is referred to Gross Vehicle Weight
Rating (GVWR). And each axle ’s
maximum loaded capacity is referred
to Gross Axle Weight Rating (GAWR).
The GVWR and each axle ’sGAWR
are shown on the vehicle certification
label affixed to the driver ’s door.
The GVWR and front and rear
GAWRs are determined by not only
the maximum load rating of tires but
also loaded capacities of the vehicle ’s
suspension, axles and other parts of