brakes AUDI R8 SPYDER 2011 User Guide

Braking
New brake pads
During the firs t 250 miles (4 00 km), new
b rake pads do not possess their f ull braking
effect, they have to be "broken in" first. The
d istance can be ten times longer in ve hicles
with ceramic brakes *. Yo u can compensate f or
this slightly reduced b rak ing power by push­
in g harder on the b rake pedal. Avoid heavy
br ak ing loads during the b reak -in period.
Operating conditions and driving habits
The brakes on today's automob iles are st ill
subject to wear, depending largely on operat­
ing conditi ons and dr iv ing habits
c:> & . On ve­
hi cles that are either driven mostly in stop­
a n d-go ci ty traffic o r are d riven ha rd, the
b rake pads should be checked by you r auth or­
iz ed A udi dealer more o ften than specifie d in
the
Warranty & Maintenan ce booklet . Fail ure
to have your b rake pads inspected can res ult
i n re duced b rake performance.
O n steep slo pes, you shou ld use the b ra kin g
effec t of the eng ine. Th is w ay, yo u prevent un­
n ecessa ry wea r on the bra ke system . If you
must use yo ur brakes, do not ho ld the bra kes
down continuously. P ump the brakes at inte r­
va ls.
Moisture or road salt
A t speed s above 70 mph ( 110 k m/h) and wit h
the windshield wipe rs swi tched
on (at le ast in ­
terval stage 4), the bra ke pads are br iefly a p­
p lied against the bra ke discs. T his occ urs at
regu lar intervals witho ut the driver noticing
and prov ides for better brake response time
u nder wet condit io ns.
Unde r ce rtain conditions, for examp le, w hen
driving thr ough water or ve ry heavy rain, or
even after was hing yo ur vehicle, the brak ing
effect ca n be red uced d ue to moisture (or in
freezing conditions ice) on the brake pads. A
few ca utious brake applicat ions should d ry off
t he bra ke pads o r rem ove any ice coa tings.
The effective ness of the brakes can be reduced
when the vehicle is dr iven o n a salt-covered
Intelligent technology 153
road and the b ra kes are no t used . Li kewise,
yo u clean off accu mulated salt coatin g from
brake d iscs and pads with a few cautio us ap ­
plications of t he brake
c:> & .
Corrosion
The re may be a tendency for di rt to build up
on the brake pads and cor ros ion to form on
the discs if t he car is not driven regu la rly or
on ly for short trips w ith litt le use of the
brakes.
If the brakes are not use d frequently, o r if cor­
r os ion has formed on the discs, it is adv isa ble
to clean off the pads and d iscs by braking
firmly a few times from a moderately high
speed
c:> & .
Faults in the brake system
If you shou ld not ice a sudden in crease i n
brake pedal trave l, t hen one of the two brake
c ir cuits may have fa iled. Dr ive immediately to
the nearest qualified wor kshop to have the
damage repaired . Dr ive at reduced speed on
the way there and ant ici pate longer stopping
dis tances and high er pedal p ress ure c:> & .
Low brake fluid level
Malfunctions can occ ur in the brake system if
the brake fluid level is too low. The brake flu id
level is monitored elect ro nica lly.
Brake power assist unit
T he bra ke power assist unit increases the
pressure that you generate w ith the brake
pedal. It work s only when the engine is run­
ning.
Brake lining wear status
B ra ke lining wear may be che cke d by visual in ­
s p ection of t he condition of the bra ke pads
th ro ugh the open ings in the wheel. If neces ­
sary, the w hee l may be removed fo r thi s i n­
spect ion
c:> page 216 .
A WARNING
- You should perform braking mane uvers
f o r th e purpos e of cleaning the brake
s ys tem only if roa d condit ions permit.
•
•

154 Intelligent technology
Other road users must not be put at risk -
you may cause an accident!
- Before descending a steep grade, reduce
speed and shift transmission into a lower
gear or lower driving position . 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 brak­ ing efficiency .
- Do not "ride the brakes" by resting 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 operating
conditions such as passing through wa­
ter, driving in heavy rain or after washing
the vehicle, the effectiveness of the
brakes can be reduced. In winter, ice can
accumulate on the brake pads, linings,
discs and drums. Cautiously apply brakes
for a test . Brakes will dry and ice coat­
ings will be cleaned off after a few cau­
tious brake applications .
- Driving for an extended period of time on
salt-covered roads without using your
brakes can also 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 air
flow to the front brakes is not obstruct­
ed. Otherwise the brake system could
overheat reducing the effectiveness of
the entire brake system.
- Failure of one brake circuit will impair
braking capability, resulting in increased
stopping distance. Avoid driving the vehi­
cle and have it towed to the nearest au­
thorized Audi dealer or qualified work­
shop.
- Never let the vehicle roll to a stop with
the engine shut off .
- If the brake booster is not working, for
example when towing your vehicle, or because the brake booster has somehow
been damaged, the brake pedal must be pressed considerably harder to make up
for the lack of booster assistance.
Power steering
When the engine is running , power steering
makes i t easier for the driver to steer.
Power steering helps the driver steer the vehi­
cle with little physical effort.
If the engine is not running, the power steer­
ing system is also not working . In this case ,
you will find it extremely difficult to turn the
steering wheel.
If you turn the steering fully to the left or
right when the vehicle is stationary, you place
a very heavy load on the power steering sys­
tem. Turning the steering wheel fully to the left or right will cause noise in the system. It
also reduces engine idle speed.
(D Note
Do not hold the steering turned fully to
the left or right for more than 10 seconds
when the engine is running . There is a risk
of damage to the power steering system .
(D Tips
-In the event of a power steering system
failure, or if the engine is not running
(while being towed), you will still be able
to steer the vehicle. However, you will re­
quire more effort to do so .
- If the power steering system has a leak
or is defective, you should immediately
contact a qualified workshop .
- The power steering system requires a
special hydraulic fluid. The power steer­
ing fluid reservoir is located in the en­
gine compartment. The correct hydraulic
fluid level is important for proper opera­
tion of the power steering system. The
power steering fluid level is checked ac­
cording to the Audi maintenance service
schedule.

158 Driving and en vi ro nm ent
Driving and
environment
Break-in period
A new vehicle must be broken in, and the break-in per iod should be 1,500 miles (2,500
km) . Do not use full acceleration for the first
600 miles (1,000 km) and do not exceed the
maximum eng ine speed of 6,000 rpm You
must also not use fu ll acce lerat ion between
600 and 1,200 mi les (1,000 to 2,000 km).
F rom 1,200 to 1,500 mi les (2,000 to 2,500
km), you can gradua lly increase maxim um en­
gine speed to 8,250 rpm for brief periods.
During the first ho urs of operation, there is
g reater friction in the engine and the trans­
mission than later when a ll the moving parts
have broken in.
The way yo u drive duri ng the first 1,500 miles
(2,500 km) affects engine quality. If you drive
at moderate engine speeds thereafter, partic ­
u lar ly when the engine is cold, yo u reduce en ­
g ine wear and increase the potential mileage
of the engine.
Do not drive at RPMs that are too low. Shift
down when the engine is no longer running
"smoothly". Extreme ly high RPMs are gov­
erned automatically.
Driving through water
on roads
Note the following to avoid vehicle damage
when dr iving through water, for example on
flooded roads:
- The water must not be any higher than the
bottom of the vehicle body .
- Do not drive faster than wa lking speed.
.&_ WARNING
After driving through water, mud, slush,
etc., the brakes may be slow to take effect
because of wet b rake roto rs and pads. Dry
t he brakes fi rst by bra king carefully to re­
sto re the full braking effect.
-
(D Note
Vehicle components such as the eng ine,
transmission, suspension or e lectrical sys­
tem can be severe ly damaged by dr iv ing
through water.
@ Tips
- Check the depth of the water before d riv­
ing through it.
- Do not stop the vehicle, drive in reverse
or switch the engine off when driving
through water.
- Keep in mind that oncoming vehicles
may create waves that raise the water
level and make it too deep for your vehi­
cle to drive through safely .
- Avo id driving through salt water because
it can cause corros ion.
Catalytic converter
You must use lead-free gasoline in your veh i­
cle, otherwise you will destroy the catalyt ic
converter.
Never run the fuel tank completely dry; their­
regular fuel supply could cause misfires . This
allows unburned fuel into the exhaust system,
poss ibly resulting in overheating and damage
to the catalytic converter .
.&_ WARNING ,-
-Do not park or operate the vehicle in
areas where the hot exha ust system may
come in co nta ct with dry g rass, brush,
fue l spills or o ther material which can
cause a fire.
- Do not app ly addition al under coating or
r u stproofing on or nea r the exhaust
manifold, exhaust pipes, catalytic con­
verter or heat shields . Dur ing driving, the
substance used for undercoating could
overheat and cause a fire.
(D Note
To ensure efficient o peration of the Emis­
s ion Control System:

-Have you r vehicle maintained properly
and in accordance with the service rec­
ommendat ions in your Warranty
& Main­
tenance booklet.
- Lack of proper maintenance as well as
improper use of the vehicle will impair
the function of the Emission Control Sys­
tem and could lead to damage.
Sporty driving
Warming up and cooling down
By carefully warming up and cooling down
your vehicle, you can he lp ensure that it is not
overstressed unnecessarily during sporty driv ­
ing.
When warming up, the vehicle is driven at a maximum engine speed of
6000 RPM
(Vl0 engine) or 7000 RPM (V8 engine) in or­
der to raise the engine oil temperature to a minimum of
140 °F (60 °(). The tires also on­
ly reach their full road holding capability once
they have warmed up .
The cooling fan can continue to run in your ve­ h icle after the engine is switched
off. H owev­
er, driving the vehicle to cool it down is part ic ­
ularly important. During sporty driving, the
engine and brakes, the exhaust system, and
the t ransm ission all become ex treme ly hot.
Before you park the vehicle, you shou ld d rive
it for a few mi les/kilometers at light load in
the low rpm range to allow it to coo l down .
Driving on a track
Before you take your vehicle out on a track,
ensure that it is in perfect condition. For ex­
ample, you should check the tire tread and the brake pads . It is best to increase t ire pressure
by about 0 .3 bar .
When driving on a track, oil consumption may be somewhat higher than in "normal" opera­
tion ¢page
180.
You shou ld definitely inspect your vehicle af­
ter subjecting it to severe condit ions. Are the
brake pads OK? Is there anything unusual
Dri vin g and en vironm ent 159
about the ti res, including the inner and outer
sidewa lls (e.g . tread, blistering)? Are the air
intakes free of leaves and tire dust? Is the o il
l evel OK?
Your authorized Audi dea ler or qua lified work­
shop will be happy to undertake an inspection
before and after use on the race track.
(D Tips
- Some race tracks (e.g . steeply banked
t u rns) may affect the response of the
ESP .
- When driven on a race track, all vehicle
parts are severe ly stressed. This can re ­
sult in increased wear.
Operation and maintenance
Fuel economy, env ironme nta l impact, and
wear on your eng ine, brakes and tires largely
depend on three factors:
- your personal driving style
- operating conditions
- technical limitations
By having your ve hicle reg ularly se rv iced by an
authorized Aud i dea ler helps to ens ure that i t
r uns properly and econom ica lly. The condition
of your veh icle not only affects its safety and
ability to ho ld its va lue, it a lso affects
f u el
con sumptio n.
The amount o f oi l used is re lated to engine
load and speed .
It is normal fo r the oil consump tion of a new
engine to reac h its lowest value after a certa in
mileage has been d riven.
You must drive your veh icle about 3,000 mi les
(5,000 kilometers) before you can p rope rly
assess oil consumpt ion.
This also app lies to fue l cons umption and en­
gine output.
(D Note
- Have your veh icle ma inta ined properly
and in accordance with the service
•
•

Cleaning and protect ion
General information
Regular core preserves vehicle value.
Regular and correct care will contribute to
maintaini ng the beauty and value of your Au­
d i. Furthermore, good care may be a condition
for substantiating a warranty cla im should
corrosion damage or paint defects occur.
Your authorized Audi R8 dealer has a variety
of
d edicat ed ve hicl e-car e produ ct s. Please
make sure you apply them correctly .
A WARNING
-Cleaning agents may be poisonous. Keep
them out of the reach of children.
- Heed all caution 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 polis h remover or other volatile
fluids . They may be toxic, flammab le or
haza rdous in other ways. Do not wash,
wa x or d ry the vehicle wi th the ign it ion
on or the eng ine running.
- Do not clean the undersides of chassis,
fenders, wheel covers, e tc. wit h out pro­
tecting your hands and arms . You may
c u t yourself on sharp -edged metal parts .
- Moist ure and ice on brakes may imp air
braking efficiency
c:> page 153, Broking.
T est the brakes carefully each time you
wash the vehicle.
@) For the sake of the environment
Select only environmentally friend ly clean­
ing products . Leftover clean ing products
should not disposed of in the household
waste .
Cleaning and protec tion 16 1
Care of exterior
Washing your vehicle
The longer i nsect rema ins, bird dropp ings,
t ree res in , ro ad and indust rial dust, tar , soo t
particles, road salt, and o ther aggressive de­
pos its remain on the vehicle su rface, the more
lasting their destructive effect will be . High
temperatures, for example from intense s un­
light, intensify the corrosive effect.
After the end of winter road salting, the un­ derside of the vehicle shou ld be thoroughly
washed .
Automatic car washes
You must t ake the necessary precautions s uch
as clos ing t he windows and convert ible top
before using an automatic car wash.
If yo ur
vehicle has specia l accessories - e.g . spoilers,
radio antenna -it is best to speak to the oper­
ator of the car wash c:>(D .
Only use car washes where the vehicle re ­
mains stationary and the cleaning equipment
moves around the veh icle while washing and
drying. It is not possib le to use car washes
where the vehicle is moved forward on a con­
veyer
c:> ,& .
It is preferab le to wash your vehicle in a
brush less carwash .
Washing with a pow er wa sher
When was hing yo ur vehicle with a power
washe r, be sure to follow the operating in ­
structions for the power washer. This applies particu larly to the
p ressure and the spra ying
distance .
Mainta in sufficient distance from
soft materials such as rubber hoses, sound
deade ning mater ial, and the park ing aid sen­
sors* that are located i n the front or rear
bumper.
Do not use washers with
a ro tating jet or a
nozzle spraying
a h igh pr essur e je t of wate r in
any case.
IJl,-
•
•

162 Cleaning and protection
Hand washing
When washing your vehicle by hand, first soft­
en the dirt with copious amounts of water and
rinse it
off as best you can.
Then clean the vehicle using a soft
sponge, an
auto glove or a low-pressure wash brush.
Work from the top down to the bottom, start­
ing with the convertible top
¢ page 163. Use
a
shampoo only for v ery stubborn dirt.
Rinse the sponge or auto glove thoroughly at
frequent intervals.
Clean the wheels, door sills and similar areas last. Use a separate sponge for this.
_& WARNING
-Car washes with conveyors can damage
the vehicle tires, which could cause the tire to lose pressure suddenly while driv­
ing and put you at risk for an accident.
Do not use car washes with conveyors.
- Switch
off the ignition when you wash
your vehicle to avoid an accident.
- Protect your hands and arms from sharp
metal edges when you clean the under­
body, the inside of the wheel wells or the
wheel covers to avoid cutting yourself.
- When washing your vehicle in the winter :
Moisture and ice in the brake system can
affect the brakes.
- Never wash tires with a jet that sprays
water in a direct stream . This could cause
invisible damage to the tires and weaken
them, even if the spray is from a relative ­
ly long distance and for a short time .
Damaged and weakened tires can fail
and cause accidents and personal injury.
(D Note
- Never drive your vehicle through any au ­
tomatic car wash that fails to provide ei­
ther sufficient clearance for your vehicle
or sufficient track width for your tires. Risk of expensive damage to the vehicle's
underbody , tires, and rims!
- As described in your Warranty
& Mainte­
nance booklet, damage or malfunction due to misuse of the vehicle or failure to
operate the vehicle in accordance with
the
instructions of this Owner's Manual
will not be covered under warranty.
- Fold the exterior mirrors flat - there is a
risk of damaging the exterior mirrors .
Power folding exterior mirrors must not
be folded in or out by hand. Use the pow­
er function!
- Do not wash the vehicle in direct sun­
light. You may damage the paint.
- Do not use sponges designed to remove
insects, rough kitchen sponges, or simi­
lar products. You risk damaging the
paint surface.
- You should remove debris (such as in­
sects) from the headlight lenses on a
regular basis, for example when refuel­
ing your vehicle. Never clean the head­
lights with a dry cloth or sponge . Use a
wet cloth or sponge .
It is best to use
soapy water.
- Never clean tires using a nozzle that
sprays water in a direct stream. Damage
can occur even with a relatively long
spraying distance and for a very short
time.
- To avoid damaging your vehicle, always
make sure that there is sufficient dis­
tance between the spray head and soft materials like rubber hoses, plastic parts
and sound-deadening materials. Never
aim the spray head at the same point for
a long time. This also applies to cleaning
headlights and painted bumpers. Re­
member: the closer the nozzle is to the
surface of the material, the greater the
stress on the material.
- Never clean the convertible top using a
power washer.
@) For the sake of the environment
Wash your vehicle only at specially de­
signed facilities. They can prevent any dirty
water contaminated by oil from entering
the waste water. In certain areas washing
a car outside of such facilities is not per­
mitted.

stickers on the inside of the rear window
over the wires.
- To he lp prevent dirt from scratching the
window, always scrape in a forward di­
rection -pus hing the scraper away from
you -never back and forth.
Weatherstrips
To seal properly, the weatherstrips around the
front lid, doors, eng ine compartment lid, etc .
must remain pliable . Spray the weatherstrips
with silicone or coat them with talcum pow­
de r or glyce rine to retain the flexibility of t he
r u bber and to protect them against free zing
in the winte r.
A WARNING
Always read and heed a ll WARNINGS and
the information
¢page 161.
@ Tips
Keep silicone sprays off the windsh ield to
avoid wiper smear in rain.
Wheels
Regular care is required to preserve the deco­
rative appearance of the wheels . Road sa lt
and brake dust must be washed off regularly
or the wheels w ill be damaged .
Use only special acid-free cleaning agents. Yo u
can find proper wheel cleaner at authorized
Aud i dea lers and specialty stores. Do not leave
the cleaner on the wheels longer than speci­
fied. Wheel cleaners containing acid can dam­
age the surface of the wheel bolts .
Paint polish or other abras ive materials must
not be used when caring for wheels. If the
protective coating has been damaged, from
stones for example, touch up the damage as
soon as possible .
A WARNING
-Moisture and ice on brakes may affect
braking efficiency-
¢page 153, Braking.
-
Cleaning and protec tion 165
Test the brakes carefully after each vehi­
cle wash.
- Always read and heed all WARNINGS and
the information
c:;, page 161.
Exhaust tail pipes
Road salt and other corrosive materials wi ll
damage the material in the exhaust tail pipes
if they are not cleaned regularly. Do not clean
the tail pipes with wheel cleaner, pa int polish,
ch rome polish or other ab ras ive cleaners.
Clean the tail pipes with car ca re p roducts
that are suitable fo r sta inless steel.
Your authorized Audi dea ler can provide clean­
ing products that have been tested and ap­
proved for your vehicle.
Care of interior
· Radio and navigation display
The display may be cleaned with a soft cloth
and commercially-ava ilable "LCD cleaner".
The cloth should be coated lightly when the clean ing solution when cleaning the display .
(D Note
To prevent scratches, only clean the dis­
play when it is dry.
Plastic parts and imitation leather
You can clean p lastic parts and imitation
leather with a damp cloth. If this does not re­
move the d irt, you can t reat these parts only
with special
so lvent-fr ee pl astic cl eaning and
care produ ct s.
A WARNING
""' ~
Solvents can change the properties of
some p lastics and make it harder for the
a irbag to deploy.
- Never clean the instrument panel or the
surface of Airbag modu les with cleaning
products that conta in solvents.
- Products containing solvents will make
the surface of this part poro us.
•
•

184 Checking and filling
Brake fluid
Notice
Have the brake fluid changed by an experi­
enc ed technician .
Brake fluid abso rbs moisture from t he a ir. If
the water content in the brake fluid is t oo
high, corrosion in the brake system may result
after a per iod of t ime . The bo iling po int of the
brake fluid w ill also decrease considerably and
dec rease b rak ing performance.
Therefore, the brake flu id must be changed
e ver y two y ear s. Always use new brake fluid
which confo rms to Fede ral Motor Vehicle
Standa rd "FMVSS 1 16 DO T 4".
Brake fluid is rep laced according to the Audi
maintena nce service schedule . Your author­
ized Audi dealer is equipped with the necessa­
ry special tools and rep lacement parts , has
the necessary expe rtise, and c an d ispose of
the used fluid .
& WARNING
-Brake fluid is po isonous. It must be sto r­
ed on ly in the closed orig inal container
o ut o f the reach of children!
- Brake fa ilure can result from old or inap ­
propriate b rake fluid . Observe these pre­
caut ions:
- Use only bra ke fluid that meets SAE
specifi cation
J 1 703 and co nfo rms to
F ederal Motor Vehicle St andard 116 .
A lways check with you r a uthorized Aud i
dea ler to make s ure you are using the
correct brake fl uid. T he correct type of
brake fluid is a lso indicated on the
brake fluid reservoir.
- The brake fluid must be new. Heavy use
of the brakes can cause a vapor lock if
the brake fl uid is left in the system too
long . This can ser ious ly affect the effi­
cie ncy of the bra kes as well as yo ur
safety. This could result in an acc ident .
(D Note
Brake fluid will damage the paint of you r
vehicle .
@ For the sake of the environment
Because o f the prob lem of p rope r disposal
of brake fluid as well as the spec ial too ls
r equired and the necessary expertise, we
recommend that yo u have the brake fl uid
changed by yo ur authorized Aud i dea le r.
Battery
General information
All work on the battery requires technical
knowledge.
The battery is located behind the cover i n the
l uggage compa rtme nt. Remove the cover by
pushing it to the left and lift ing it o ut.
The battery is practically maintenance-free
and is checked as pa rt of your ve hicle's main­
tenance se rv ices .
You are we ll advised to replace a battery that
is older than S years .
Disconnecting the battery terminal s
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 . To prevent th is, the battery
shou ld only be disco nnected from the ve hicle
electrica l system when abso lutely necessary
f o r repai rs.
Vehicles not driven for long periods
The battery becomes d ischarged due to quies­
cent current consume rs even when the vehicle
i s not used . With extended pe riods of non-use
i n the
cold season, you should have the ve hi­
cl e battery removed by an autho rized Aud i
de aler or qu alified workshop and stored in an
frost -free place. This preven ts the battery
from "freezing" and thereby being dest royed.
D uring the
warmer seasons it is eno ugh to liJ>

190 Tire s and wheel s
-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.
Glossary of tire and loading terminology
Accessory weight
means t he comb ined we ight (in excess of
those standard items which may be rep laced)
of R t ron ic, powe r stee ring, powe r brakes,
power w indows , power sea ts, r ad io , a nd hea t­
e r, to the extent that these i tems are available
as facto ry -in stalled equipment (whether in ­
stalled or not).
Aspect ratio
means t he ratio o f the heigh t to the w idth of
the tire in percen t. Numbers of 55 or lower in­
d icate a low sidewall fo r improved s teer ing re ­
sponse and better overall handling on dry
pavement.
Bead
means t he pa rt of the t ire that is made o f
steel wires, wrapped o r reinforce d by p ly cor ds
and that is shaped to fi t the r im.
Bead separation
means a b reakdown of the bond between
components in the bead.
Cord
means the s trands forming the plies in the
tire .
Cold tire inflation pre ssure
means t he tire pressure recommended by the
ve hicle manufacture r for a tire of a designated
si ze that has not been dr iven for more than a
couple of miles (kilometers) at low speeds in
the three hour period before the tire pressure i s measu red or adjusted. -
If you notice un usua l vibration or if the
veh icle pulls to one side when driv ing, a l­
ways stop as soon as it is safe to do so and check the wheels and tires for dam­
age.
Curb weight
means the we ight of a motor ve hicle w ith
standard equipment includ ing the max imum
capa city of fuel, o il, and coolant, a ir cond i­
ti on ing and addi tional weig ht o f option al
equipmen t.
Extra load tire
means a tire designed to operate at higher
loads and at highe r inflat ion p ress ures tha n
the cor responding standard tire . Extr a load
t ir es my be i dent ified as "XL", "xl", "E X T RA
LO AD", or "RF" on t he sidewall.
Gross Axle Weight Rating ( "GAWR ")
means the load-carry ing capacity of a s ingle
axle system , measured at the tire-ground in­
te rfaces .
Gross Vehicle Weight Rating ( "GVWR ")
means the maximum total loaded we ight of
the vehicle.
Groove
means the space between two adjacent tread
ribs .
Load rat ing (code )
means the maximum load that a tire is rated
to carry fo r a given inflation press ure. Yo u
may not fi nd this information on all tires be­
ca use it is not required by law.
Maximum load rating
me ans the lo ad r ati ng for a tire a t the m axi­
mum perm issib le inf lation pressure for that
ti re .

Maximum loaded vehicle weight
means the sum of:
(a) Curb weight
(b) Accessory weight
(c) Vehicle capacity weight, 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 pressu re."
Normal occupant weight
means 150 lbs. (68 k ilograms) times the
nu mber 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 e levations due to labeling, decorations, or
protective bands or ribs.
Ply
means a layer of rubber-coated para llel cords.
Production options weight
means the comb ined weight of those installed
regular production options weighing over 5
lbs . (2 .3 kg) in excess of those standard items
which they replace, not previously considered
in curb weight or accessory weight, including
heavy duty brakes, r ide leve lers, roof rack,
heavy duty battery, and specia l trim .
Radial ply tire
means a pneumatic t ire in which the p ly cords
that extend to the beads are laid at substan­
tially 90 degrees to the centerline of the
tread.
Tires and wheels 191
Recommended inflation pressure
see ~ page 190, Cold tire inflation pressure.
Reinforced tire
means a t ire designed to operate at higher
loads and at higher inflat ion pressures than
the corresponding standard tire. Re inforced
ti res my be ident ified 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 d iameter of the bead seat. If
you change your wheel s ize, you w ill have to
purchase new tires to match the new r im di­
ameter.
Rim size designation
means r im diameter and width.
Rim width
means nom inal distance between rim fla nges.
Sidewall
means that portion of a tire between the
tread and bead.
Speed rating (letter code)
means the speed at which a tire is designed to
be driven for extended periods of time. The
ratings range from 93 mph (150 km/h) to
186 mph (298 km/h)
~ page 200 . You may
not find this information on all tires because
it is not requ ired by law.
T he speed rating letter code, where applica­
ble, is molded on the tire sidewall and indi­
cates the maximum pe rm issib le road speeds
~ .&. in Winter tires on page 204.
Tire pressure monitoring system
means a system that detects when one or
more of a veh icle's tires are underinflated and
illuminates a low tire pressure warning tell­
tale.
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