brake AUDI A4 SEDAN 2013 Workshop Manual

196 Trailer towing
Trailer towing Driving with a trailer
General information
Your Audi was designed primarily for passen­
ger transportation .
If you plan to tow a trai ler, p lease remember
that the additional load will affect durability,
economy and performance .
Trailer towing not on ly places more stress on
the vehicle, it also calls for more concentra­
tion from the driver.
For this reason, always fo llow the operating
and driving instructions provided and use
common sense.
Technical requirements
Trailer hitch Use a weight-carrying hitch conforming to the
gross trailer weight. The hitch must be suita­
ble for your vehicle and trailer and must be
mounted securely on the veh icle's chassis at a
technically sound location. Use only a trailer
hitch with a removable ball mount. Always
check with the trailer hitch manufacturer to
make sure that you are using the correct
hitch.
Do not use a bumper hitch.
The hitch must be installed in such a way that
it does not interfere with the impact-absorb­
ing bumper system . No modifications should
be made to the vehicle exhaust and brake sys­
tems . From time to time, check that all hitch
mounting bolts remain securely fastened.
When you are not towing a trailer, remove the
trailer hitch ball mount. This prevents the
hitch from causing damage should your vehi­
cle be struck from behind
¢ A.
Trailer brakes
If your tra iler is equipped with a braking sys­
tem, check to be sure that it conforms to a ll
regulations . The trailer
hydraulic brake system must not be
direct ly connected to the vehicle's hydraulic
brake system
~ A.
Safety chains
Always use safety chains between your vehicle
and the trai le r.
Trailer lights
T railer lights must meet all regulations. Be
sure to check w ith your authorized Audi dealer
for correct wiring, sw itches, and relays.
Mirrors
If you are unable to see the traffic behind you
using the regular outside mirrors, then you
must install extended mirrors . It is important
that you
always have clear vis io n to the rear.
,8. WARNING
- If a trailer has electrical brakes please
note that these brakes are not activated
by the factory-fitted control unit -risk of
accident!
- Afte r removing the trailer hitch, do not
store it in your vehicle. In case of sudden
braking, the hitch could fly forward and
injure you or your passengers.
Operating instructions
Maximum trailer weight
-
A trailer for your vehicle is limited to a typical
class 1 or class 2 tra iler.
Trailer load distribution Be sure the load in the trailer is held secure ly
in place to prevent it from shifting forward,
backward or sideways.
Never allow a passenger to ride in a trailer
¢ A in Driving instructions on page 197.
Engine cooling system
T owing a trailer makes the engine work hard ­
er. It is important that the cooling system's
performance is up to the additional load.
Make sure that the cooling system has enough
fluid . .,..

Tire pressure
When towing a trai le r, inflate the t ires of your
vehicle to the co ld tire pressure listed under
"Full load" on the label located on the driver's
side B-pillar (vis ible when the door is open).
Inflate trailer tires to trailer and tire manufac­
turers' specifications.
Light s
The headlight settings should be checked with
the trailer attached before driving off. Check
to make sure both vehicle and trai ler lights
are working properly.
Safety chains
Be su re tra iler sa fety chains are properly con­
nected from the trailer to the hitch on the ve­
hicle. Leave enough slack in the chains to per ­
mit turning corners . When you install safety
chains, make sure they w ill not drag on the
road when you are driving.
The chains shou ld cross under the trai ler
tongue to prevent it from dropping in case of
separatio n from the hitch .
Driving instructions
Driving with a trailer always requires extra
core and consideration.
To obtain the best possible handling o f vehicle
and trai ler, p lease note the following:
.,. Do not tow a loaded trailer whe n your car it­
self is not loaded .
.,. Be especia lly careful when passing other
vehicles .
.,. Observe speed limits .
.,. Do not drive at the maximum permissible
speed .
.,. Always apply brakes ea rly .
.,. Monitor the temperature gauge.
Weight di stribution
Towing a loaded trai ler with an empty car re­
sults in a highly unstable distribution of
weight . If this cannot be avo ided, drive at very
low speeds only to avoid the risk of losing
steer ing control.
Trailer towing 197
A "balanced" rig is easier to operate and con­
trol. This means that the tow vehicle should be loaded to the extent possible and permissi­
ble, while keep ing the trailer as light as possi­
ble under the c ircumstances. Whenever poss i­
ble, transfer some cargo to the luggage com ­
partment of the tow vehicle while observing
tongue load requirements and vehicle loading
considerations.
Speed
The higher the speed, the more d iff icult it be­
comes for the driver to control the rig . Do not
drive at the maximum permissible speed. Re­
duce your speed even more if load, weather or
wind conditions are unfavorable -pa rticularly
when going downhill.
Reduce veh icle speed
immediately if the trail­
er shows the slightest s ign of sway ing .
Do not
try to stop the swaying by accelerating.
Observe speed limits . In some areas, speeds
for vehicles tow ing tra ilers are lower than for
regular vehicles .
Always apply brakes early. When driving downh ill, shift into a lower gear to use the en ­
gine braking effect to slow the vehicle . Use of
the brakes alone can cause them to overheat
and fail.
Coolant temperature
The coolant temperature gauge ¢ page 10
must be observed carefully . If the need le
moves close to the upper end of the scale, re­
duce speed immediately and/or turn off the
air conditioner.
If the coolant temperature warning light •
in the instrument cluster starts flashing, pull
off the road, stop and let the engine
idle for
about two minutes to prevent heat build -up .
A WARNING
Anyone not properly restrained in a mov ­
ing vehicle is at a much greater risk in an
accident . Never let anyone ride in yo ur car
who is not properly wearing the restraints
prov ided by Audi.
-
•
•

198 Trailer towing
Trailer towing tips
Important to know
Your vehicle hand les different ly when tow ing
a trailer because of the addit ional weight and
different weight distribution . Safety, perform­
ance and economy wi ll greatly depend on how
carefully you load your trailer and operate
your rig.
Before you actually tow your trailer, practice
turning, stopp ing and backing up in an area
away from traffic. Keep practicing until you have become completely familiar with the way
your veh icle-trailer combination behaves and
responds.
Backing up is difficult and requires practice.
Backing up with a trai ler generally requires
steering action opposite to that when backing
up your vehicle without a trailer.
Maintain a greater distance between your ve­
hicle and the one in front of you. You will need
more room to stop. To compensate for the
trailer, you will need a larger than normal
turning radius .
When passing, remember that you cannot ac­
celerate as fast as you normally would be­
cause of the added load. Make sure you have
enough room to pass . After passing, allow
plenty of room for your tra iler before chang­
in g lanes again.
Avoid jerky starts, sharp turns or rapid lane
changes.
(D Tips
- Do not tow a tra iler dur ing the break-in
period of your vehicle.
- If you tow a trailer, your Audi may re­
quire more frequent maintenance due to
the extra load
q page 2 72.
Parking on a slope
Do not park on a slope with a trailer . If it can­
not be avoided, do so only after doing the fol­ lowing :
When parking:
.. App ly the foot brake.
.. Have someone place chocks under both the
vehicle and the trailer wheels .
.,. With chocks in place, slowly release the
brakes until the wheel chocks absorb the
load.
.. Tur n the wheels towards the curb.
.. App ly the parking b rake.
.. Place an automatic transmission* in P, re­
spectively a manual transmission in first or reverse gear.
When restarting after parking:
.. App ly the foot brake .
.. Start the engine.
.. Move the se lector lever to D/S, respectively
a manual transmission in first gear.
.. Release the parking brake and slow ly pu ll
out and away from the wheel chocks.
.. Stop and have someone retr ieve the wheel
chocks .
(D Tips
If you move the selector lever of the auto­
matic transmission* to P before applying
the parking brake and before blocking the
whee ls, you may have to use more force
lat er to move the lever out of the P posi­
tion.

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.
Furthermore, good care may be a condition
for substantiating a warranty claim should
corrosion damage or paint defects occur.
Your authorized Audi dealer has a variety of
dedicated vehicle-care products and can ad­
vise which ones to use for cleaning the exter i­
or and interior of your vehicle.
Whether you use products recommended by
Audi or other commercially available cleaning
agents, please make sure you apply them cor­
rectly .
.&, 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 carefully.
- 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 polish remover or other volatile
fluids. They may be toxic, flammab le or
haza rdous in other ways. Do not wash,
wax or dry the vehicle with the ignition
on or the engine running.
- Do not clean the undersides of chassis,
fenders, wheel covers, e tc. without pro­
tecting your hands and arms. You may cut yourself on sharp-edged metal parts.
Cleaning and protection 199
-Moisture and ice on brakes may impair
brak ing effic iency¢
page 187. Test the
brakes carefully each time you wash the
veh icle.
@) For the sake of the environment
Select on ly environmentally friend ly clean­
i ng products . Leftover cleaning products
should not d isposed of in the household
waste.
Care of exterior
Washing
Frequent washing protects the vehicle .
The best protection against environmental i n­
fluences is
frequent washing and waxing . How
often th is 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 seasonal and weather conditions
- Environmental influences
T he longer b ird droppings, insects, tree resin,
road and indus trial gr ime, tar, soot, road salt
and other materials remain on the vehicle
body, the more lasting their destructive ef­
fects will be . High temperatures caused by ex­
posure to intense sun light intens ify the corro­
sive effect, particularly when humid ity is high
as well.
Under certain circumstances,
weekly washing
may be necessary. Under other cond itions, a
monthly washing and waxing may be ade­
quate .
After the winter, the underside of the vehicle
should be thoroughly washed, preferab ly in a
professional car wash .
.&, WARNING ,_
Always read and heed all WARNINGS and
other information¢
page 199 .
•
•

204 Cleaning and protec tio n
Cast (light) alloy wheels
Cast (light) alloy wheels require special care .
• Wash the whee ls with a sponge or hose
brush every other week.
• For deep cleaning afterwards, use only a
dedicated
aci d-fr ee cast alloy wheel cleaner .
• Rub a coat of
liq uid wax onto the r ims every
t h ree month . Be sure to reach and treat a ll
parts of the rim .
To preserve the decorat ive appearance of the
cast alloy whee ls, some specia l care is neces­
sa ry. In addit ion to road dirt and sa lt, b rake
d ust is a lso corros ive. If left on for too long,
b rake dust can cause pitting.
Use only specia l
acid-free cleaners formulated
for a lloy rims . Safe p roducts are available at
your author ized Audi dealer. Never leave the
cleane r on the rims longe r than specified on
the label. If not rinsed off promptly, the acid
contained in some cleaners can attack the
threads on the whee l bolts.
Never use ab rasive or metal polishing clean­
ing agents. If the protective coating has been
chipped, e .g. by k icked up road dirt, touch it
up as soon as possible.
A WARNING
- Moisture and ice on brakes may affect
braking efficiency ¢
page 187. Test the
brakes carefully each time you wash the
vehicle .
- Always read and heed all WARNINGS and
other information ¢
page 199.
-
Body cavity sealing
The body cavity sealing does no t need to be
checked.
A ll body cavities which co uld be affected by
corrosion have been thoroughly protected at
the factory.
This sealing does not require any inspection or
addit ional treatment . If any wax should seep
out of the cav ity when the ambient tempera- ture is high, it can be removed with a p
lastic
scraper and a suitable solvent.
A WARNING
-Solvents can be dangerous.
- Benzine is flammab le and toxic. If you
use benzine for removing the wax, keep
sparks, flame and lighted cigarettes
away. Never dump benz ine on the
ground, into open streams or down sew­
age drains.
- Be sure to observe all safety and environ­
mental regulat ions . Follow all instruc ­
tions on the container .
- Always read and heed all WARNINGS and
other information ¢
page 199.
, Chassis
Have the undercoating checked for damage
from time to time.
The lower body shell of your Audi is also thor­
oughly protected against corros ion.
Any damage to the undercoating caused by road hazards should be repaired prompt ly .
A WARNING
Too much undercoating in the wrong p la­
ces can cause a fire.
- Do not app ly additional undercoating or
r u stproof ing 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 199.
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, pa int polish,
chrome polish or other ab rasive cleaners.
Clean the tail pipes with car care products
that are suitable for stainless steel.

216 Checking and filling
-Apply the parking brake.
- Move selector lever of automatic trans- mission to "P" (Park); put manual trans­
mission in Neutral.
- Always let the engine cool down. Hot
components will burn skin on contact.
- To reduce the risk of being burned, never
open the hood if you see or hear steam
or coolant escaping from the engine
compartment . Wait until no steam or
coolant can be seen or heard before care­
fully opening the hood .
- Keep children away from the engine com­
partment .
- Never spill fluids on hot engine compo­
nents. They can cause a fire.
- Never touch the radiator fan. The auxili­ ary electric fan is temperature controlled
and can switch on suddenly.
- Never open the coolant reservoir cap when the engine is still warm. The cool­
ant system is pressurized and hot cool­
ant could spray out .
-Protect your face, hands and arm from
steam or hot engine coolant by placing a
thick rag over the cap when you open the coolant reservoir .
- Do not remove the engine cover under
any circumstances. This increases the
risk of burns.
- If work on the fuel system or the electri­
cal system is necessary:
- Always disconnect the battery .
- Never smoke or work near heaters or
open flames. Fluids in the engine com­
partment could start a fire.
- Keep an approved fire extinguisher im­
mediately available.
- To avoid electrical shock and personal in­
jury while the engine is running or being
started, never touch:
- Ignition cables
- Other components of the high voltage
electronic ignition system.
- If you must perform a check or repair with the engine running: -
First, fully apply the parking brake,
move selector lever of automatic trans­
mission to "P" (Park); put manual
transmission in Neutral.
- Always use extreme caution to prevent
clothing, jewelry, or long hair from get­
ting caught in the radiator fan, V-belts
or other moving parts, or from contact­ ing hot parts. Tie back hair before
starting, and do not wear clothing that
will hang or droop into the engine.
- Minimize exposure to emission and
chemical hazards~&, .
.&_ WARNING
California Proposition 65 Warning:
- Engine exhaust, some of its constituents,
and certain vehicle components contain
or emit chemicals known to the State of
California to cause cancer and birth de­
fects and reproductive harm. In addition, certain fluids contained in vehicles and
certain products of component wear con­
tain or emit chemicals known to the
State of California to cause cancer and
birth defects or other reproductive harm.
- Battery posts, terminals and related ac­
cessories contain lead and lead com­
pounds, chemicals known to the State of
California to cause cancer and reproduc­
tive harms. Wash hands after handling.
(D Note
When adding fluids, always make sure that
they are poured into the proper container
or filler opening, otherwise serious dam­
age to vehicle systems will occur.
@ For the sake of the environment
To detect leaks in time, inspect the vehicle
floor pan from underneath regularly . If
you see spots from oil or other vehicle flu­ ids, have your vehicle inspected by an au­
thorized Audi dealer.

Checking and fillin g 217
Engine compartment
Engine compartment
These are the most important items that you can check.
Fig. 167 Typical layout for containers and engine oil filler cap
(D Eng ine oi l filler cap ( @ Jump start point(+) under a cov-
er .. .. ... ....... ........ .. 228,263
@ Brake fl uid reservo ir
((0)) . . . . . 224
@ Coolant expansion tank (J-) . . . 223
® Jump start point(-) with hex
head screw ..... .......... .. 228, 263
® Windshie ld/headlight* washer
container
(0) . . . . . . . . . . . . . . 229
The pos ition of the engine o il fi lling hole
¢ fig . 167 (item @) can differ depending on
the eng ine design.
A WARNING
-
Before yo u check anything in the engine
compartment, always read and heed all
WARNINGS¢ &. in Working in the engine
compartment on page 215.
Engine oil
Engine oil specifications
The engine oil used in your Audi needs the
right kind of oil .
The eng ine in your Audi is a sophisticated
power p lant that was bu ilt to exacting specifi­
cations . This eng ine needs the right k ind of
engine oil that meets specifications regarding
quality and viscosity so that it can run
smooth ly and reliab ly. Choosing the rig ht o il
and changi ng oil within the t ime and mileage
i n tervals printed in you r vehicle's Warranty
&
Maintenance booklet matters a lot more to ­
day than it did years ago . Audi has developed
a specia l quality standard for engine oil that
will help assure that your vehicle's engine w ill
get the lubr ication it needs for proper opera-
tion. .,..

224 Checking and filling
scalding from hot coolant by following
these steps.
- Turn off the eng ine and a llow it to cool
down.
- Protect your face, hands and arms from escaping flu id and steam by cover ing
the cap with a large, thick rag.
- Turn the cap slowly and very carefully
i n a counter-clockwise direction while
apply ing l ight, downwa rd p ress ure on
the top of the cap .
- To avo id being burned, do not sp ill an­
tifreeze or coolant on the exhaust sys­
tem or hot engine parts . Under certain
conditions, the ethylene glyco l in en­
gine coolant can catch f ire .
- Antifreeze is poisonous . Always store an­
tifreeze in its or iginal container and we ll
out of the reach of children .
- If you drain the coolant, it must be
caught and safely stored in a proper con­
tainer clear ly marked "poison".
@ Note
- Coolant po llutes the env ironment and
could cause an engine fire . Excess coo l­
ant will be forced out through the pres­
sure relief valve in the cap when the en­
gine becomes hot.
- If, in an emergency, on ly water can be
added, the correct ratio between water
and antifreeze
c::> page 222 must be re­
stored as soon as possible .
@ For the sake of the environment
Drained coolant should not be re used. Al­
ways dispose of used coolant while observ­
ing all environmental regulat ions.
Radiator fan
The radiator fan switches on automatically by
itself
The radiator fan is driven by the engine via the
V-be lt . The viscous clutch regulates the speed
of the fan according to the temperature of the
coolant. An a
uxiliary electric radiator fan* switches on
and off depending on coolant temperature
and other vehicle operat ing condit ions .
After yo u sw itch the engine off, the aux iliary
f an can continue running for up to 10 minutes
- eve n wit h the ignition off. It can even switc h
on again later by itself
c::> &. , if
- t he tempe rature of the engine coo lant rises
due to the heat build -up from the engine in
the engine compartment, or
- the engine compa rtment heats up because
the vehicle is parked in i ntense sunlight.
_& WARNING
- To reduce the risk of personal in jury nev­
er touch the radiator fan.
- The auxiliary electric fan is temperat ure
controlled and can sw itch on suddenly
even when the engine is not running.
- The a uxiliary radiator fan sw itches on a u­
tomatically when the engine coo lant
reaches a certai n temperature and will
continue to run until the coolant temper­
ature drops.
Brake fluid
Checking brake fluid level
The brake fluid level can be checked with a
quick glance.
F ig . 17 1 Eng ine compartment: Cover on the brake flu­
i d reservo ir
Before you check a nyth ing in the engine com­
partment,
always read and h eed all WARN ­
INGS c::> .&. in Working in the engine compart-
ment on page 215. .,..

~ Read the brake fluid level from the brake
fluid reservoir ¢
fig. 171, ¢ page 217,
fig . 167.
T he brake fluid level must be be ­
tween the "MIN" and "MAX" markings.
The brake f luid reservoir is located at the rear
partition of the engine compartment on the
l eft side ¢
page 217 .
The fluid level may drop slightly after some
time due to the automatic adjustment of the brake pads . This is not cause for alarm .
If the brake fluid level falls considerably be­
l ow the "M IN" mark, the bra ke wa rning/ind i­
cator light (U .S . mode ls:
1111 , Canadian
models: .) will come on
¢ page 15. Do not
continue to operate the vehicle. The complete
brake system shou ld be thoroughly checked
by an authorized Audi dealer or qualified
workshop and the cause co rrected . If the
b rake fluid level is too low, the b rake wa rn ing/
i nd icator lig ht w ill illuminate . Co ntact an a u­
thor ized Audi dealer immediately.
@ Tips
The brake f luid rese rvoir is located unde r­
neath the cove r.
Changing brake fluid
Have the brake fluid changed by an experi­
enc ed technician .
Brake fluid ab sorbs moisture from the a ir. If
the water content in the brake fluid is too
hi gh, corrosion in the b rake system may result
after a per iod of t ime . The bo iling po int of t he
b ra ke fluid w ill also decrease con siderab ly and
d ec rease brak ing per forman ce.
Therefore, the brake flu id must be changed
every two year s. Always use new b ra ke fluid
which confo rms to Fede ral Motor Vehicle
S tand ard "FMVSS 1 16 DOT 4".
The brake flu id rese rvoir can be difficult to
r eac h, therefo re , we recommend that yo u
have the brake fl uid changed by yo ur aut ho r­
iz ed Audi dealer. Your dealer has the correc t
Checking and fillin g 225
tools, the right brake fl uid and t he know -how
to do this for you .
A WARNING
- Brake fl uid is poisonous. It must be stor­
ed only in the closed or iginal container
out of the reach of children!
- Brake failure can res ult from o ld or inap­
propriate brake f lu id. Observe these pre­
cautions:
- Use only brake fluid th at mee ts SA E
spe cificat ion
J 17 03 and conforms to
Fe dera l Mo to r Ve hicl e Standard 1 16.
Always check with yo ur autho rized Au di
dealer to make sure yo u are using the
correct brake fluid. The c orrect type of
brake f luid is also ind icated on t he
brake f luid reservoir .
- The bra ke fl uid must be new. Heavy use
of the brakes ca n cause a vapor lock if
the b rake fluid is left i n the system too
long. This can se riously affect the effi­
c iency of the b rakes as well as your
safety , T his could result in an accide nt.
(!) Note
Brake fluid will damage the pai nt of your
vehicle.
@) For the sake of the environment
Because of the prob lem of proper disposal
of brake fluid as well as the spec ial too ls
r equired an d th e nec essary exper tise, w e
r ecomme nd that yo u have th e brake flu id
c hanged by yo ur aut ho rize d Aud i dea le r.
Battery
General information
U nder normal operating cond itions, the bat­
te ry in your Audi does not need any ma inte­
nance . With
high outside temperat ures or
lo ng da ily drives we recommend that you have
t h e e lectrolyte leve l che cked by an autho riz ed
A udi de aler or qu alified workshop. The elec­
tro lyte leve l should also be checked e ach time
the battery is charged
¢ page 2 28 . 1J1>
•
•

232 Tires and wheels
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 pressu re
to which a tire may be inflated. Also called
"maximum inflation p ressure."
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 inf lated 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 parallel 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 tir e in which the p ly cords
that extend to the beads are laid at substan­
tially 90 degrees to the centerline of the
tread . Recommended inflation pressure
see
~
page 231, Cold tire inflation pressure.
Reinforced tire
means a t ire design to operate at higher loads
and at h igher inflation pressures than the cor­
responding standard tire. Reinforced tires
may be identified as "XL", "xl", "EXTRA LOAD",
o r "R F" on the sidewall.
Rim
means a metal support for a tire or a t ire 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 will have to
purchase new tires to match the new rim di­
ameter .
Rim size designation
means rim diameter and width.
Rim width
means nominal distance between rim flanges.
Sidewall
means that portion of a tire between the
t read 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 242. You may
not find this information on all tires because
it is not requ ired by law.
The speed rating letter code, where applica­
ble , is molded on the tire sidewall and indi­
cates the max imum perm issible road speeds
~ A in Winter tires on page 246.
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.