brakes AUDI TT 2013 Owner´s Manual

154 Intellig ent technolog y
down continuously. Pump the brakes at inter ­
va ls.
Noises may occur when braking depending on
the speed, braking force and outside condi­
tions such as temperature and humidity.
Moistu re or road salt
Under certain conditions, for examp le, when
d riving through water or ve ry heavy rain, or
even after washing your vehicle , the bra king
effect can be reduced due to moisture (o r in
freezing conditions ice) on the brake pads. A
few cautious brake applications should dry off
the brake pads or remove any ice coatings.
The effectiveness of the b rakes can be reduced
when the vehicle is driven on a salt -covered
road and the brakes are not used. Likewise,
you clean off accumulated sa lt coating from
brake discs and pads with a few caut ious ap­
plications of the brake
q .&. .
Co rrosion
There may be a tendency for dirt to bui ld up
on the brake pads and corrosion to form on
the discs if the car is not driven regularly or
only for short trips with little use of the brakes.
If the brakes are not used frequently, or if cor­ rosion has formed on the discs, it is advisable
to clean off the pads and discs by braking
f irmly a few times from a moderately high
speed
Q .&. .
Fa ults in th e brak e system
If you should notice a sudden increase in
brake peda l travel, then one of the two brake
circu its may have failed
q .&. .
Low brake flu id le vel
Malfunct ions can occur in the brake system if
the brake fluid level is too low. The brake fluid
leve l is monitored electronically.
B rake boo ste r
The brake booster increases the press ure that
you gene rate w it h the brake pedal. It works
on ly when the engine is running
.Q .&.
Brake lining wear statu s
Brake lining wear may be checked by visual in­
spection of the condition of the brake pads
thro ugh the openings in the wheel. If neces­
sary, the wheel may be removed for this in­
spection
q page 224, What should I be
aware of when changing a tire?.
A WARNING
-- You shou ld perform braking maneuvers
for the purpose of cleaning the brake system only if road conditions permit .
Othe r road use rs must not be put at risk -
you may ca use an accident!
- Before descend ing a steep grade, reduce
speed and sh ift transmission into a lower
gear or lower dr iving range. Do not ride
the brakes or hold the pedal down too
long or too often. This could cause the
brakes to get hot and diminish braking
efficiency.
- Do not "ride the brakes" by rest ing your
foot on the pedal when you do not intend
to brake. This may cause the brakes to
overheat, premature wear and increased
stopping distance .
- Under certain climatic and operat ing
conditions such as passing through wa­
ter, dr iving in heavy rain or after washing
the vehicle, the effectiveness of the b rakes can be reduced. In winte r, ice can
accumu late on the bra ke pads, lin ings,
d iscs and drums. Carefully app ly bra kes
for a test . Brakes will dry and ice coat­
ings will be cleaned off after a few care­
fu l brake applications.
- Driving for an extended period of time on salt-covered roads without using your brakes can a lso affect braking efficiency.
Clean off accumulated salt coating from
brake discs and pads with a few cautious
brake applications .
- If you damage the front spoiler, or if you
install a different spoiler, be sure the a ir
f low to the front brakes is not obstruct-
ed. Otherwise the brake system could
Ill>

Driving and
environment
The first 1
1000
miles
(11500 km) and
afterwards
New engine
The engine needs to be run-in during the first
1,000 miles (1 ,500 km) .
For the first 600 mile s (1,000
kilometre s):
.,. Do not use full throttle .
.,. Do not d rive at engine speeds that are more
than 2/3 of the max imimum permitted
RPM .
.. Avoid hig h engine speeds.
From 600 to 1,000 miles (1 ,000 to
1,500 kilometres):
.. Speeds ca n gradually be increased to th e
maximum pe rm iss ib le road or eng ine speed .
During and after break-in period
.. Do not rev the engine up to high speeds
when it is cold . T hi s applies whether the
transmission is in N (Neutral) o r in gear.
After the break- in period
.. Do not exceed max imum eng ine speed un­
der any circumstances .
.. Upshift into the next higher gear
before
reaching the red area at the end of the tach­
ometer scale
<::;> page 10.
During the first few hours of driving, the en­
g ine 's inter na l friction is higher than later
when all the moving pa rts have been broken
i n. How well this break-in p rocess is done de­
pends to a considerable ex tent o n the way t he
ve hicl e is driven d uring the first 1,000 miles
(1, 500 kilome tres) .
(D Note
Extremely high engine speeds a re auto­
mat ic al ly reduced. However, t hese RPM-
Driving and environment 159
limits were programmed for an eng ine
well run-in, not a new eng ine.
@ For the sake of the environment
Do not d rive wi th unnecessar ily h igh en­
gine speeds -upshifting ear ly saves f uel,
r educes noise and protects the environ­
ment.
New tires
If your vehicle is running on new tires, drive
particularly carefu l for the first 350 miles
(S00 ki lometres) after fitting .
A WARNING
-New tires tend to be s lippery and must a l-
so be "broken-in". Be s ure to remembe r
this dur ing t he firs t 3S 0 m iles (500 kilo­
me tres) . Brake gent ly . Avo id following
closely behind other vehicles or other sit­ uations that m ight require sudden, hard
b raking.
New brake pads
Remember that new brake pads do not have a
full brak ing effect during the first 250 miles
(400 kilometres) after they are installed.
New brake pads have to be "burnished in" be­
fore they have optima l grab¢ .&..
D uring the break-in period, yo u should avoid
putting seve re loads on the brakes . Severe
l oads include, for example, su dden hard brak­
ing, in particular at very h igh speeds or, for
example, on mou nta in passes.
A WARNING
Until t hey develop the maximum "bite" fo r
best stopping power, the s urfaces on new
b rake pads requ ire some "brea king- in" dur­
in g the initial 10 0 to 150 miles (15 0 to
20 0 kilome tres) of normal c ity dr iv ing. Yo u
can compensate for this by press ing the
b rake peda l more f irm ly . This applies
whenever new pads are installed.
•
•

160 Driving and en vironm ent
Avoid damaging the
vehicle
When you are driving on poor roads, or over
curbs, steep ramps, etc ., make certain that
low-lying parts such as spoilers and exhaust
system parts do not bottom out and get dam­
aged.
This is especially true for vehicles with low­
slung chassis (sports chassis) and fully loaded
vehicles .
Driving through water
on roads
Note the following to avoid vehicle damage
when driving through water, for example on
flooded roads:
- T he water must not be any highe r tha n the
bottom of the vehi cle body.
- Do no t drive faster than wa lking speed.
_& WARNING
After d riving through water, m ud, slush,
etc., the brakes may be slow to take effect
because o f wet brake ro tors and pads . Dry
the brakes fi rst by braking carefully to re­
store the full braking effect.
(]) Note
Vehicle components such as the engine,
transmiss ion, suspension or electrical sys ­
tem can be severely damaged by driving
through water.
- Check the depth o f the water before driv ­
ing through it.
- Do not stop the veh icle, dr ive in reverse
or switch the engine
off when driving
through water.
- Keep in mind that oncoming vehicles may c reate waves that raise the water
l evel and make it too deep for your vehi­
cle to drive through safely.
- Avoid driving thro ugh salt water because
it can ca use corrosion.
-
Catalytic converter
It is very important that your emission con­
trol system (catalytic converter) is function­
ing properly to ensure that your vehicle is run­
ning in an environmentally sound manner.
.,. Always use lead-free gasoline ¢ page 176,
Fuel supply .
.,. Never run the tank down all the way to
empty .
.,. Never put too much motor o il in your en-
gine ¢
page 185, Adding engine oil 'l::r. .
.,. Never try to push- or tow-sta rt you r vehicle.
The catalyt ic converter is an efficient "clean­
u p" dev ice buil t into the exhaust system of
t h e vehi cle. The cata lytic conve rter bu rns
many of t he pollu tan ts in the exha ust gas be­
f ore they are re leased into the atmosphere.
T he exclusive use of unleaded fuel is critica lly
important for the life of the catalyt ic convert­
er and prope r fu nct ion ing of the engine.
A WARNING
- Do not park or operate the vehicle in
areas where the hot exha ust system may
come in contact with dry g rass, brush,
fue l spill or other material wh ich can
cause a fire.
- Do not app ly additiona l undercoating or
rustproofing on or near the exhaust
manifold, exhaust pipes, catalytic con­
verter or heat sh ields. Dur ing driv ing, the
substance used fo r undercoating could
overheat and cause a fire.
(D Note
- Be aware that just one tank filling with
leaded fuel will already ser iously de-
grade the performance of the catalytic
converte r.
- Do not exceed the correct engi ne oil level
¢page 185.
-Do not drive until the fuel tank becomes
completely empty . The engine co uld mis-
fire. Unburned fuel could also get into ..,.

the exhaust system and this could cause
the catalytic converter to overheat.
- Do not turn off the ignition while the ve ­
hicle is moving .
- Do not con tinue to operate yo ur vehicle
under these conditions, as otherwise fuel
can reach the cata lytic converter . This
could result in overheating of the con­
verter, requ iring its replacement.
- To assure efficient operation of the Emis­
sion Control System:
- Have your veh icle ma inta ined properly
and in acco rdance with the service rec­
ommendations in your Wa rranty
&
Ma intenan ce booklet.
- Lac k of proper maintenance as well as
improper use of the vehicle will impa ir
t he funct ion of the emission control
system and cou ld lead to damage.
@ For the sake of the environment
Even when the Emission Contro l System is
operating p roperly, the exhaus t gas can
have a s ulfu r- like exhaust gas smell under
some operating states. This depends on
the s ulfur content o f the fue l being used.
Using a different brand of fuel may help,
or filling the tank w ith lead-free super
grade gasoline .
Operate your vehicle
economically and
minimize pollution
General
Your personal style of driving will determine
the economy of your vehicle, as well as ex­
haust and noise levels .
Fuel economy, environmental impact, and
wear on your engine, brakes and t ires largely
depend on three factors :
- your persona l driving style
- operating conditions
- technical lim itations
I f you anticipate w hat you need to do nex t and
d rive economically, you can eas ily cut your
Dri vin g and en vironm ent 161
fuel consumption by 10 -15 percent. Th is sec ­
tion w ill give yo u some tips on how you can
help the env ironment and your pocketbook .
(D Tips
The cons umption estimates as published
by ENVIRONME NTAL PROTEC TION AGENCY
(EPA) and Transport Canada may not corre­
spond to your actual consumption on the road, which will vary depending upon vehi­
cle load and speed, road and weather con­
dit ions, trip length, etc.
Drive smoothly and keep a lookout
ahead
Vehicles use the most fuel when they are ac­
celerating.
Avoid unnecessary accelerat ing and braking .
Vehicles use the most fuel when they are ac­
ce lerat ing . If you anticipate what is going to
happe n next, you will need to brake less and,
th us, accele rate less. Let the vehicle coast
whenever possible -for examp le when you see
that the next t raff ic light is red.
Avoid full throttle
Driving at moderate speeds saves fuel and
improves your mileage.
"' Try and keep well below your car's maxi -
mum speed.
Acce lerat ing gently reduces fue l consump­
tion, eng ine wear, and does not disturb the
environment.
Fuel consumpt ion, exhaust emiss ions and en­
gine noise increase disproportionately at high
speeds. If you drive at approximately three
quarte rs of top speed, fuel consumption w il l
be reduced by one half. Never drive faster
t h an the posted speed limit and weathe r con­
ditions perm it.
•
•

164 Cleaning and protection
Cleaning and
protect ion
General information
Regular core preserves vehicle value .
Any automobile is exposed to industrial
fumes, corrosive road salt, etc. A well cared
for Audi can look like new many years after purchase . Regular and correct care w ill con­
tr ibute to maintaining the beauty and value of
your Aud i.
Furth erm ore, goo d car e m ay be a c onditi on
for substantiat ing a warrant y claim shou ld
c orrosion dam age or paint d efe ct s occ ur.
Your author ized Audi dealer has a variety of
d ed ica ted vehicl e-ca re product s and can ad ­
vise which ones to use for cleaning the exter i­
or and inte rior of your vehicle .
Whether you use products recommended by
Aud i or other commercially ava ilable clean ing
agents, please make sure you apply them cor­
rectly .
A WARNING
-Cleaning agents may be poisonous. Keep
them out of the reach of children.
- Heed all caut ion labels.
- Always read directions on the container
before using any product . Follow the di­
rect ions carefu lly.
- Most chemical cleaners are concentrated
and have to be diluted.
- Use spot removing fluids only in well
ventilated areas.
- Do not use gasoline, kerosene, d iesel
fuel, nail pol ish remover or other volati le
fluids. They may be toxic, flammab le or
hazardous in other ways. Do not wash,
wax or dry the vehicle with the ignit ion
on or the engine running.
- Do not clean the undersides of chassis,
fenders, wheel covers, etc. without pro­
tecting your hands and arms. You may
c u t yourself on sharp-edged metal parts . -
Moisture and ice on brakes may impair
brak ing eff ic iency
c::> page 153 , General
information.
Test the brakes carefully
each time you wash the vehicle .
@ For the sake of the environment
Select on ly environ mentally friendly clean­
i ng products. Leftover cleaning products
should not d isposed of in the househo ld
waste .
Care of exterior
Washing
Frequent washing protects the vehicle .
The best protection against environmental in ­
fluences is
frequent washing and waxing . How
often this is required depends on:
- How much the veh icle is used
- Where the veh icle is parked (garage, in the
open under trees, etc.)
- The seasona l and weather conditions
- Environmental infl uences
T he longer b ird droppings, insects, tree resin,
road and indus tria l gr ime, ta r, soot, road salt
and other materials remain on the vehicle paint, the more lasting their destructive ef­
fects wi ll be .
High tempera tures, as from expos ure to in­
tense sunlight, intensify the corrosive e ffect
particularly when humidity is high as well.
Under certa in ci rc u mstances,
we ekly washing
may be necessary. Unde r othe r cond it ions, a
monthly washing and waxing may be ade ­
quate.
After the winter, the unders ide of the vehicle
sho uld be thoro ughly washed p re ferab ly in a
pro fessional ca r wash.
A WARNING ~
A lways read and heed all WARNINGS and
the information
c::> page 164.

~ Wipe the windows dry with a clean piece of
cloth or kitchen paper towel.
The best way to remove snow from windows
and mirrors is to use a brush. Use a non-abra­
sive
plastic ice scraper -better still, a spray
deicer -to remove
ice from windows and mir­
rors.
The windows must not be cleaned with insect
remover or wax since these can interfere with
the function of the windshield wiper blades
(chatter).
Oil, grease or silicone residue can be removed
with
glass cleaner or silicone remover. How­
ever, wax residue requires the use of a special­
ly formulated solvent. Please contact your
Audi dealer for advice on safe products for
wax removal.
Windows should also be cleaned on the inside
at regular intervals.
Never dry windows with the same chamois
that you use to dry painted surfaces. Wax resi­
due on the chamois can impair vision through
the windows.
A WARNING
-The windshield must not be treated with
water-repellent materials. They can in­
crease glare under poor visibility condi­
tions such as wetness, darkness, or when
the sun is low on the horizon. In addi­
tion, they can cause the windshield wip­
ers to chatter.
- Always read and heed all WARNINGS and
other information
¢page 164.
(D Note
-Never use warm or hot water to remove
snow and ice from windows and mirrors.
This could cause the glass to crack.
- To prevent damage to the wires of the
rear defogger, do not place any adhesive
stickers on the inside of the rear window
over the wires.
- To help prevent dirt from scratching the
window, always scrape in a forward di-
Cleaning and protection 169
rection -pushing the scraper away from
you -never back and forth.
· Steel wheels
Applies to vehicles : with steel wheels
The wheels also have to be cleaned.
~ Always include the hub caps and wheel rims
when washing your vehicle to remove road
dirt, salt sprays and brake dust.
If necessary, use a commercial wheel cleaner
to remove accumulated brake dust.
The wheel rims are easier to keep clean if they
are regu larly coated with liquid wax.
Paint scratches should be touched up as soon
as possible to prevent corrosion
¢ page 168,
Touch-up paint.
A WARNING
-Moisture and ice on brakes may affect
braking efficiency -
¢ page 153, General
information.
Test the brakes carefully af­
ter each vehicle wash.
- Always read and heed all WARNINGS and
the information
¢page 164.
Cast (light) alloy wheels
Applies to vehicles: with Cast alloy wheels
Cast (light) alloy wheels require special care.
~ Wash the wheels with a sponge or hose
brush every other week.
~ For deep cleaning afterwards, use only a
dedicated
acid-free cast alloy wheel cleaner .
~ Rub a coat of liquid wax onto the rims every
three month. Be sure to reach and treat all
parts of the rim.
To preserve the decorative appearance of the
cast alloy wheels, some special care is neces­ sary. In addition to road dirt and salt, brake
dust is also corrosiv e. If left on for too long,
brake dust can cause pitting.
Use only special
acid-free cleaners formulated
for alloy rims. Safe products are available at
your Audi dealer. Never leave the cleaner on .,..
•
•

170 Cleaning and protection
the rims longer than specified on the label. If
not rinsed off promptly, the acid contained in
some cleaners can attack the threads on the
wheel bolts.
Never use abrasive or metal polishing clean­
ing agents. If the protective coating has been
chipped, e.g. by kicked up road dirt, touch it
up as soon as possible.
A WARNING
-Moisture and ice on brakes may affect
braking efficiency¢
page 153, General
information.
Test the brakes carefully
each time you wash the vehicle.
- Always read and heed all WARNINGS and other information
qpage 164.
Body cavity sealing
The body cavity sealing does not need to be
checked.
-
All body cavities which could be affected by
corrosion have been given thorough protec­
tion at the factory.
This sealing does not require any inspection or
additional treatment. If any wax should seep
out of the cav ity when the ambient tempera­
ture is high, it can be removed with a plastic
scraper and a suitable solvent.
A WARNING
, -
Solvents can be dangerous.
- Benzine is flammable and toxic. If you use benzine for removing the wax, keep
sparks, flame and lighted cigarettes
away. Never dump benzine on the
ground, into open streams or down sew­
age drains.
- Be sure to observe all safety and environ­
mental regulations. Follow all instruc­
tions on the container.
- Always read and heed all WARNINGS and
the information
¢page 164.
Chassis
Have the undercoating checked for damage
from time to time.
The lower body shell of your Audi is also thor­
oughly protected against corrosion.
Any damage to the undercoating caused by
road hazards should be repaired promptly.
A WARNING
-Too much undercoating in the wrong pla-
ces can cause a fire.
- Do not apply additional undercoating or
rustproofing on or near the exhaust
manifold, exhaust pipes, catalytic con­
verter or heat shields. While driving, the
substance used for undercoating could
overheat and cause a fire.
-Always read and heed all WARNINGS and
other information¢
page 164.
Exhaust tail pipes
Road salt and other corrosive materials will
damage the material in the exhaust tail pipes
if they are not cleaned regularly. Do not clean
the tail pipes with wheel cleaner, paint polish, chrome polish or other abrasive cleaners.
Clean the tail pipes with car care products
t h at are suitable for stainle ss steel.
Your authorized Audi dealer can provide clean­ ing products that have been tested and ap­
proved for your vehicle.
Care of interior
Radio-/Navigation* display
.. Clean the display with a soft clean cloth and
an LCD cleaner.
The display can be cleaned with a professio­
nally available "LCD cleaner ". The cloth should
be slightly dampened with the cleaning fluid
to clean the display. .,.

190 Checking and filling
If the brake fluid level falls considerably b e­
l ow the "MIN" mark, the brake warning/ indi­
cator light (U .S . mode ls:
1111 , Canad ian
model s:. ) will come on
c> page 14 . Do not
continue to ope ra te the vehicle. The comple te
brake system shou ld be thoroughly checked
by an author ized Audi dealer or ot her quali­
fied fac ility and the cause corrected . If the
b rake fluid level is too low, the b rake war ning/
i ndicator ligh t w ill illuminate. Contact an a u­
thor ized A udi dealer
immediatel y.
Changing brake fluid
Hove the broke fluid changed by on experi­
enced technician.
Brake fl uid abso rbs moist ure from the a ir. If
the wate r content in the b ra ke fluid is too
h igh, cor ros ion in the br ake sys tem may result
after a per iod of t ime . The bo iling point of the
brake fluid wi ll also decrease considerab ly and
decrease braking performanc e.
Therefore, the brake fl uid mus t be changed
every tw o year s. Always use new b rake fluid
which conforms to Federal Motor Veh icle
Standard "FMVSS 1 16 DOT 4".
The brake flu id rese rvoi r can be difficul t to
r each, therefo re , we recommend that yo u
have the brake f luid changed by yo ur autho r­
ized
Audi dealer. Your dea ler has the correct
too ls , the right brake f luid and the know-how
to do this for you.
A WARNING
- Brake fluid is poiso nous . It must be stor­
ed only i n the closed orig inal container
o ut o f the reac h of children!
- Brake fa ilure can result from old o r inap ­
propriate b rake fluid . Observe these pre­
caut ions :
- Use only bra ke fluid that meets SAE
specif ication
J 1 703 and co nforms to
Federal Motor Vehicle Standard 116 .
Always check with your a uthori zed Audi
dealer to ma ke sure you are using the
correct brake flu id. The correct type of brake flu
id is also ind icate d on the
brake f lu id rese rvoir.
- The brake fluid must be new. Heavy use
of the brakes can cause a vapo r lock if
the brake fluid is left in the system too
long. This can seriously affect the effi­
c iency of t he brakes as well as your
safety . T his co uld resu lt in a n accide nt.
([) Note
Brake fluid will damage the paint of your
vehicle.
@ For the sake of the environment
Because o f the prob lem of proper disposal
of brake fluid as well as the spec ial too ls
required and the necessary expertise, we
recomme nd that you have the brake flu id
changed by yo ur autho rize d Aud i deale r.
Battery
General information
Your vehicle is equipped with a specia l bat ­
tery, an
ACM battery. This battery is located
in the luggage compartment and must be re­
placed with an origina l equipment battery .
U nder normal opera ting condit ions, the bat­
te ry is
maintenance-fr ee .
Have the battery checked when you take your
vehicle in for serv ice . You a re well advised to
replace a battery that is o lde r th an 5 years .
Disconnecting the battery terminals
Some vehicle functions (power window reg u­
lators, for example) are lost if the battery te r­
mina ls are disconnected . T hese functions have
to be relearned after the battery termina ls are
connected again . T o p revent t his, t he battery
shou ld only be disconne cted from the veh icle
elect ric a l sys tem when abso lutely ne cessary
f or rep air s.
Vehicles not driven for long periods
If you do not drive your vehicle ove r a period
of seve ral days o r weeks , e lectr ica l compo-
nents a re g radually cut back or switched off.
Ill-

-Never mount used tires on yo ur vehicle if
yo u are not sure of their "previous histo­
ry." Old used tires may have been dam­
aged even though the damage cannot be
seen that can lead to sudden tire failure
and loss of vehicle control.
- If you notice unusual vibration or if the
vehicle pulls to one side when d riving, al­
ways stop as soon as it is safe to do so
and check the wheels and tires for dam­
age .
(D Note
Please note that summe r and wi nte r tires
are designed for the cond itions that are
Glossary of tire and loading terminology
Accessory weight
means the comb ined weight (in excess of
those sta ndard items which may be rep laced)
of au toma tic transmission, power steer ing ,
power brakes, power windows, power seats,
radio, and heater, to the extent that these
items are availab le as factory-installed equip­
ment (whether installed or not) .
Aspect ratio
means the rat io o f the height to the w idth of
the tire in percent . Numbers of 55 or lower in ­
dicate a low sidewall for improved steering re­
sponse and better overa ll handling on dry
pavement .
Bead
means the part of the t ire t hat is made o f
steel wires, wrapped or reinforced by ply cords
and that is shaped to fit the r im.
Bead separation
means a b reakdown of the bond between
components in the bead .
Cord
means the strands forming the plies in the
tire.
Tire s an d wheel s 197
typica l in those seasons . Aud i recommends
using winter tires during the winter
months . Low temperatures signif icant ly
dec rease the e lasticity of summer t ires,
which affects tract ion and brak ing ability.
If summer t ires are used i n very co ld tem ­
peratures, cracks ca n form o n the tread
bars , res ulting in perma nen t tire damage
that can cause loud driving noise and un­
bala nced ti re s. Audi i s not respon sible for
th is type of damage .
Cold tire inflation pressure
means the tire p ress ure recommended by t he
vehicle manufacture r fo r a tire o f a des ignated
s ize t hat has not bee n driven for more than a
coup le o f miles (k ilometers) at low speeds in
the three hour period before the tire press ure
is m easured or adjusted.
Curb weight
me ans the we ight of a motor ve hicle with
st andard equipmen t incl ud ing the max imum
capacity of fuel, oi l, and coolant, air condi ­
tioning and additional weig ht of optiona l
equipment.
Extra load tire
means a t ire designed to operate a t higher
loads and at higher inflat ion p ress ures than
the corresponding standar d tire. Extra load
ti res may be ident ified as "XL", "xl", "EXTRA
LOAD", or "RF" on the sidewall.
Gross Axle Weight Rating ("GAWR")
me ans the lo ad-ca rry ing capa city of a si ngle
axle system, measured a t the tire -ground in­
te rfaces.
Gross Vehicle Weight Rating ("GVWR ")
mea ns the maximum total loaded we ight of
the ve hicl e. .,.. •
•

198 Tires and wheels
Groove
means the space between two adjacent tread
ribs .
Load rating (code)
means the maximum load that a tire is rated
to carry for a given inflation pressure. You
may not find this informat ion on all tires be­
cause it is not req uired by law.
Maximum load rating
means the load rating for a t ire at the max i­
mum permissible inflation pressure for that
tire.
Maximum loaded vehicle weight
means the sum of:
(a) Curb weight
(b) Accessory weight
(c) Vehicle capacity we ight, and
(d) Production options weight
Maximum (permissible) inflation pressure
means the maximum cold inflation pressure
to which a tire may be inflated. Also called
"maximum inflation pressure ."
Normal occupant weight
means 150 lbs. (68 kilograms) times the
number of occupants seated in the vehicle up
to the total seating capacity of your vehicle .
Occupant distribution
means distribution of occupants in a vehicle.
Outer diameter
means the overa ll diameter of an inflated new
tire.
Overall width
means the linear distance between the exteri­
ors of the sidewalls of an inflated tire, includ ­
ing elevations due to labeling, decorations, or
protective bands o r ribs .
Ply
means a layer of rubber-coated parallel cords.
Production options weight
means the combined weight of those insta lled
regular production options weighing over 5
lb s. (2 .3 kg) in excess of those standard items
which they replace, not previously considered
in curb weight or accessory we ight, including
heavy duty brakes, ride levelers, roof rack,
heavy duty battery, and special tr im .
Radial ply tire
means a pneumat ic tire in which the ply cords
that extend to the beads are laid at substan­
t ia lly 90 degrees to the center line of the
tread .
Recommended inflation pressure
see <=> page 19 7, Cold tire inflation pressure.
Reinforced tire
means a t ire designed to operate at higher
loads and at higher inflation pressures than
the cor responding standard tire. Reinf orced
ti res may be identified as "XL" , "xl", "E XTRA
LOAD", or "RF" on the sidewall.
Rim
means a metal support for a tire or a tire and
tube assembly upon which the tire beads are
seated.
Rim diameter
means nom inal diameter of the bead seat. If
you change your wheel s ize, you will have to
purchase new tires to match the new rim di­
ameter.
Rim size designation
means r im diameter and width .
Rim width
means nominal distance between rim flanges.
Sidewall
means that portion of a tire between the
tread and bead.