tire pressure AUDI A4 2017 Owners Manual

Table of content s
Multimedia connections . . . . . . . . . . . . . . 215
P laying m edia . . . . . . . . . . . . . . . . . . . . . . . 217
Addit iona l sett ings . . . . . . . . . . . . . . . . . . 220
Suppo rted media and file formats . . . . . . 223
Troubleshoot ing. . . . . . . . . . . . . . . . . . . . . 224
Audi smartphone interface . . . . . . 227
Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227
Operating . . . . . . . . . . . . . . . . . . . . . . . . . . 227
Troubleshoot ing . . . . . . . . . . . . . . . . . . . . . 228
System settings . . . . . . . . . . . . . . . . . . 229
Sett ing the date and time . . . . . . . . . . . . . 229
MMI sett ings . . . . . . . . . . . . . . . . . . . . . . . 229
Con nection manager . . . . . . . . . . . . . . . . . 230
System update . . . . . . . . . . . . . . . . . . . . . . 23 2
So und setti ngs .. .... ......... .... .. .
Volume sett ings .... .. ..... ... .. .. .. .
R estarting the M MI . .. ..... ... .. .. .. .
Software license information 233
233
234
235
Safety first .
.. ... .. ..... ... .. .. ... 23 6
Driving safety . . . . . . . . . . . . . . . . . . . . 236
General notes . . . . . . . . . . . . . . . . . . . . . . . 236
Correct seating position for passengers . . 23 7
Driver's and fron t passenger's footwell . . 240
Pedal area . . . . . . . . . . . . . . . . . . . . . . . . . . 241
Storing cargo co rrectly . . . . . . . . . . . . . . . 242
Repo rting Safety Defects . . . . . . . . . . . . . . 243
Safety belts . . . . . . . . . . . . . . . . . . . . . . 245
Gene ral information . . . . . . . . . . . . . . . . . 24 5
W hy use safety belts? . . . . . . . . . . . . . . . . 246
Safety bel ts . . . . . . . . . . . . . . . . . . . . . . . . 248
B el t tensioner ... ... ... .... ... .. .. ... 251
Airbag system . . . . . . . . . . . . . . . . . . . . 25 3
I mportant inform ation . . . . . . . . . . . . . . . 253
Fr ont ai rbags . . . . . . . . . . . . . . . . . . . . . . . 257
M onitoring the Advanced Airbag System . 265
K nee airbags. . . . . . . . . . . . . . . . . . . . . . . . 269
Side airbags . . . . . . . . . . . . . . . . . . . . . . . . 271
Side curtain airbags ........... .... ... 274
Child safety . . . . . . . . . . . . . . . . . . . . . . 277
Important information . . . . . . . . . . . . . . . 277
Ch ild seats . . . . . . . . . . . . . . . . . . . . . . . . . 283
Secur ing ch ild seats . . . . . . . . . . . . . . . . . . 288
4
LATCH system (Lower anchorages and
tethers for c hildren) . . . . . . . . . . . . . . . . . 291
Additional informat ion . . . . . . . . . . . . . . . 295
Maintenance and Care . . . . . . . . . . . 296
Checking and Filling . . . . . . . . . . . . . 296
Gasoline . . . . . . . . . . . . . . . . . . . . . . . . . . . 296
Diesel fuel . . . . . . . . . . . . . . . . . . . . . . . . . 297
Refueling . . . . . . . . . . . . . . . . . . . . . . . . . . 298
Se lective catalytic reduction (AdBlue) . . . 300
Emissions control systems . . . . . . . . . . . . 303
En gine compartment .. ............. . .
E ngine o il ... .. .. .. .. .. ........... . .
Cooli ng sys tem . .. .. .. ............. . .
B rake fl uid . ... .. .. .. .. .. .. .... ... . .
Battery ... .. .. .. .. .. ... . .. .... ... . .
Windshie ld washer system .. ..... ... . .
Service interva l display 304
306
3
10
311
312
316
316
Wheels .. .. .. .. .. .. ... . .. .... ... .. 317
Wheels and t ires . .. .. ............... 317
Tire pressure monitoring indicator . . . . . . 334
Care and cleaning . . . . . . . . . . . . . . . . 337
General information . . . . . . . . . . . . . . . . . 337
Car washes . . . . . . . . . . . . . . . . . . . . . . . . . 337
Cleaning and care information . . . . . . . . . 338
Plac ing your vehicle out of serv ice . . . . . . 342
Troubleshooting . . . . . . . . . . . . . . . . . 343
Emergency assistance . . . . . . . . . . . 343
T runk escape latch . . . . . . . . . . . . . . . . . . . 343
Genera l information . . . . . . . . . . . . . . . . . 343
E q ui pment . . . . . . . . . . . . . . . . . . . . . . . . . 343
T ire mobility kit . . . . . . . . . . . . . . . . . . . . . 343
Replacing wheels . . . . . . . . . . . . . . . . . . . . 3 45
Space -sav ing spa re tire . . . . . . . . . . . . . . . 349
Fuses and bulbs ... ... . .. .... ... .. 351
Fuses.. ... .. .. .. .. .. .. .. .. .... ... .. 351
Bul bs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355
Emergency situations . . . . . . . . . . . . 356
Genera l . . . . . . . . . . . . . . . . . . . . . . . . . . . . 356
Start ing by push ing or tow ing . . . . . . . . . . 356
Start ing with j umper cables . . . . . . . . . . . 356
Using the jump start cable . . . . . . . . . . . . 357

<( a, .... N ,....
N .... 0 0
3 a,
on a monochrome display. The. or u centra l
indicator light turns on at the same time to indi­
cate the priority of these ind icator lights.
Red indicator lights
--------------
Central indicator light
c::> page26,
Aud i pre sense*
c::> page 10 7
USA models:
Brake system ../
c::> page 29
Canada models :
Bra ke system ../
c::> page 29
USA models:
Electromecha nical parking brake
c::> page 30
Canada models:
Electromechanica l parking brake
c::> page30
Cooling system
c::> page 31
E ng ine oi l pressure
c::> page 32
Eng ine oil level
c::> page 32
Generator
c::> page 31
Safety belt
c::> page 31
Electromechanical steering../
c::> page 13 7
Steering lock
c::> page 32
E ng ine start system
c::> page32
Transmission
c::> page 87
Adapt ive cruise control*../
c::> page 98
Congestion assist*
c::> page 104 Cockpit overview
Ad B lue*
c::> page 300
Ad Blue*
c::> page 300
Yellow indicator lights
--------------
Central indicator light
c::> page 26
E lectronic Stabilization Contro l
(ESC)
c::> page 32
El ectronic Stabilization Control
(ESC) ../
c::> page 32
Electronic Stabiliza tion Control
(ESC)
c::> page 13 5
Brake system
c::> page 33
USA models:
Anti-lock braking system (ABS)../
c::> page 32
Canada models:
Anti-lock b raking system (ABS)../
c::> page 32
Safety systems ../
c::> page 33
USA models:
Brake pads
c::> page 33
Canada models:
Brake pads
c::> page 33
El ectromechanical parking brake
c::> page 30
T ire pressure
c::> page 335
Tire pressure
c::> page 335
Engine control
c::> page 33
Engine contro l (diese l engine)
c::> page 33
27

Driving
next traffic light is red . This produces an engine
braking effect, which helps to protect the brakes
and tires and reduces the emissions and fue l con ­
sumpt ion to zero (fuel shut-off during decelera­
t ion).
Shift effici ently
An effective way to save fuel is to upshift earlier.
Staying in a gear too long uses fue l unnecessari ­
ly .
P ress down o n the acce lerator peda l slowly and
avoid "kick -down".
Avoid full acceleration
You shou ld rare ly t rave l at the maximum vehicle
speed. High speeds cause a disp roportiona tely
h igh inc rease in fuel consump tion, emissions and
traffic no ise . Slower driving saves fuel.
Reduce idling time
The Start/Stop system* he lps to reduce the idling
time automatically. In vehicles witho ut the Start/
S top system* , it is efficient to swit ch the eng ine
off when stopped at r,;1ilro,;1d crossi ngs and long
red lights . Stopping the engine for 30 -40 sec ­
onds already saves more fuel than the amount of
extra fuel needed to restart the engine.
It t akes a very long time in idle to war m the en ­
g ine up to opera ting tempera ture . Wea r and
emissions are especially high in the warm -up
p hase . Therefore, yo u should begin driving im ­
mediately after starting the engine. Avoid high
RPMs while do ing th is.
Have maintenance performed regularly
By having ma intenance performed regularly on
your vehicle, you can help to reduce f uel con­
sumpt ion befo re yo u even start to dr ive. The
maintenance condition of your vehicle not only
affects t raffic safety and long-term value but a l­
so impacts
fuel consumpt ion . A poorly main ­
tained engine can lead to f uel consumption that
is 10% higher than normal.
Avoid short trips
The engine and exhaust cleaning system m ust
reach the ir opt imal
operating temperature to ef­
fectively reduce consumption and em iss ions.
74
A cold engine uses a d isproportionately high
amount of fue l. The engine reaches operating
temperat ure and cons umption norma lizes on ly
after approximate ly
four ki lometers.
Check the tire pres sure
To save fue l, make sure the t ires are always in­
flated to the correct press ure
¢ page 32 7. The
fuel consumpt ion can increase by S% if the pres ­
s u re is only 0.5 bar too low. Due to the increased
roll ing resistance, low tire pressures w ill also
l ead to greater tire
wear and will affect dr iving
behavior.
Do not drive on
winter tires year-round, as this
will consume up to 10% more f uel.
Eliminate unnecessary we ight
Since eve ry kil og ram o f extra weight in creases
fuel consumption, a quick inspection of the lug­
gage compartment may be worth it to avoid un­
necessary we ight.
When no t be ing used, a roof rack sho uld be re ­
moved to decrease the wind resistance of the ve­
hicle . You will save approx imately
12% of your
fuel when at speeds from 62-75 mph (100-120 km/h).
Save energy
The eng ine drives the generator, which generates
electricity; the fuel consumption also inc reases
with the demand for e lectricity. Therefore, switch
e lectrical equ ipment off when you no longer
need it. Examples of eq uipment that uses a lot of
energy are air blowers at a high setting, the rear
window defogger and seat heating* .
(D Note
Do not leave engine idling unattended after
starting . If warning lights shou ld come on to
i ndica te improper operation, they would go
unheeded . Extended idling also prod uces
h eat, w hic h could result i n overheating o r
o ther damage to the veh icle o r othe r prope r­
ty .

Trailer towing
Trailer towing
Driving with a trailer
General information
Your Audi was designed primarily for passenger
transportation.
If you plan to tow a trailer, please remember that
the additional load will affect durability, econo­my and performance.
Trailer towing not on ly places more stress on the
ve hicle, it also ca lls for more concentration from
the dr iver.
F or this reason, always follow the operating and
driving instructions provided and use common
sense.
Technical requirements
Trailer hitch
Use a weight-carrying hitch conforming to the
gross tra iler weight. The hitch must be suitab le
for your veh icle and tra iler and must be mounted
securely on the vehicle's chassis at a technically
sound
locat ion . Use on ly a trailer hitch with a re­
movable ba ll mount . Always che ck with the t rail ­
er hitch man ufac tur er to make s ure t hat you are
using the co rrect hi tc h.
Do not use a bumper hitch.
The hitch must be installed in such a way that it
does not interfere with the impact -absorbing
bumper system. No mod ificat ions should be
made to the vehicle exhaust and b rake systems .
Fr om t ime to t ime, che ck that all hitch mo unti ng
bol ts rem ain securely f aste ned.
W hen you are not tow ing a tra iler, remove the
tra ile r hitc h ba ll mount . This prevents the hit ch
from caus ing damage s hou ld your veh icle be
s truck from be hind ¢
,&..
Trailer brakes
If you r trailer is equipped with a brak ing system,
check to be su re that it conforms to all regula­
tions .
90
The t rai ler hydraulic bra ke system must not be
directly connected to the vehicle's hydraulic
bra ke system ¢&. .
Safety chains
Always use s afety chains be tween you r vehi cle
and t he tra ile r.
Trailer lights
Traile r lights must meet all regula tions . B e s ure
to check w ith your author ized Audi dealer for cor­
r ec t wir ing, swi tches and relays.
Mirrors
If you are unable to see t he traffic behind you us­
i ng t he regular outs ide mirrors, then yo u
must in­
stall ex tended mirrors . It is impo rtant that you
al ways have clear vision to the rear.
.&_ WARNING
Afte r remov ing the tra ile r hi tc h, do not s tore
it i n y our vehicle. In case o f su dden brak ing,
the hitch could fly fo rward and injure you or
your passengers.
Operating instructions
Maximum trailer weight
A tra iler f or yo ur vehicle is lim ite d to a typical
class 1 or class 2 trailer.
Trailer load distribution
Be sure the load in the t rai le r i s he ld se curely in
pla ce to p reve nt i t from shi fting forwar d, bac k­
ward or si deways.
Never allow a passenger to ride in a trailer ¢ &.
in Driver messages on page 91.
Engine cooling system
Towi ng a tra iler makes the engine work harder. It
is important that the cooling system's perform ­
ance is up to the additional load . Make sure tha t
the coo ling system has enoug h fluid.
Tire pressure
When towing a trailer, inflate the tires of your
vehicle to the cold tire p ressure listed under "Full
load" on the t ire press ure label. The t ire pressure
1111-

Driving sa fe ty
Driving safety
General notes
Safe driving habits
Please remember -safety first!
This chapter contains important information,
tips, instruct ions and warn ings that you need to
read and observe for your own safety, the safety
of your passengers and others. We have summar­
ized here what you need to know about safety
be lts, a irbags, child restra ints as well as child
safety. Your safety is for us
priority number 1 . Al­
ways observe t he i nfo rmation and wa rn ings in
this section - for your own safety as well as tha t
of yo ur passengers.
The information i n this section applies to all
model ve rsions of your vehicle . Some of the fea­
tures descr ibed in t his sec tions may be s tanda rd
eq uipment on some models, or may be optional
equipment on others. If yo u are not sure, ask
your author ized Audi dealer.
A WARNING
-Always make sure that you follow the in­
structions and heed the WARNINGS in th is
manual. It is in your inte rest and in the in­
te rest of your passengers .
- Always keep all of the Owner's Lite rature
manuals in your Audi when you lend o r sell
yo ur vehicle so that this important informa­
t ion w ill always be availab le to the dr iver
and passenge rs.
- Always keep the Owner 's Lite rature handy
so that you can find i t easi ly if yo u have
ques tions.
Safety equipment
The safety features are part of the occupant re­
straint system and work together to help reduce
the risk of injury in a wide variety of occident si t­
uations.
Your safety and the safety of yo ur passenge rs
should not be left to chan ce. Advan ces in tech­
nology have made a var iety of features av ail ab le
to help reduce t he risk of injury in an accident .
236
The following is a list of just a few of the sa fety
features in your Audi :
- sophis tic ated safety be lts fo r dr ive r and all pas-
senge r seat ing pos itions,
- safety belt p re tensioners,
- be lt height adjustment for the front seats,
- head restraints for each seating position,
- front airbags,
- knee airbags fo r the front seats,
- side airbags in the front seats and outboard
rear seats *,
- side curtain airbags,
- special LA TC H anchorages for the outboard rear
seats and top tether anchorages for chi ld re ­
straints for all of the rear seats,
- adjustab le steering col umn.
These ind iv idual safety features, can work to­
gether as a system to he lp protect you and your
pa ssengers in a wide range of a cciden ts. These
fea tures canno t wo rk as a sys tem if they a re not
a lways cor rec tly ad juste d and cor rect ly used.
Safety is everybod y's responsibilit y!
Important things to do before driving
Safety is everybody's job! Vehicle and occupant
safety always depends on the informed and care­
ful driver .
For your safety a nd the safety of your passen ­
gers,
before driving alway s:
.,. Make sure that all lights and signals are operat­
ing correctly .
.,. Make sure that the tire pressure is correct .
.,. Make sure that a ll windows a re clean and afford
good v is ibility to the outs ide.
.,. Se cur e all luggage and othe r items ca refully
q page 242.
.,. Make sure that noth ing can i nter fere with the
peda ls .
.,. Adjust front seat, head restraint and mirrors
correctly for yo ur height.
.,. Instruct passengers to adjust the head re­
straints according to their he ight .
.,. Make sure to use the rig ht child restraint co r­
rectly to protect chi ldren
q page 2 77 , Child
safety. ..,.

<( a, .... N ,....
N .... 0 0
3 a,
-Never leave your vehicle unattended espe­
cially with the rear lid left open. A child
could crawl into the vehicle through the lug­
gage compartment and close the rear lid be­
coming trapped and unable to get out . Be­
ing trapped in a vehicle can lead to serious
personal injury.
- Never let children play in or around the vehi­
cle.
- Never let passengers ride in the luggage
compartment. Vehicle occupants must al­
ways be properly restrained in one of the ve­
hicle's seating positions.
-Air circulation helps to reduce window fog­
ging . Stale air escapes to the outside
through vents in the trim panel. Be sure to
keep these slots free and open.
- The tire pressure must correspond to the
load. The tire pressure is shown on the tire
pressure label. The tire pressure label is lo­
cated on the driver's side B-pillar. The tire
pressure label lists the recommended cold
tire inflation pressures for the vehicle at its
maximum capacity weight and the tires that
were on your vehicle at the time it was man­
ufactured. For recommended tire pressures
for normal load conditions, please see chap­
ter
c:> page 328.
Tie-downs
The luggage compartment is equipped with four
tie-downs to secure luggage and other items.
Use the tie-downs to secure your cargo properly
c:> page 242, Loading the luggage compar tment.
In a collision, the laws of physics mean that even
smaller items that are loose in the vehicle will
become heavy missiles that can cause serious in­
jury . Items in the vehicle possess energy which
vary with vehicle speed and the weight of the
item. Vehicle speed is the most significant factor .
For example, in a frontal collision at a speed of
30 mph (48 km/h) , the forces acting on a 10-lb
(4 .5 kg) object are about 20 times the normal
weight of the item. This means that the weight
Driving safety
of the item would suddenly be about
200 lbs. (90 kg) . You can imagine the injuries
that a 200 lbs. (90 kg) item flying freely through
the passenger compartment could cause in a col­
lision like this.
A WARNING
= -
Weak, damaged or improper straps used to
secure items to tie-downs can fail during hard
braking or in a collision and cause serious per­
sonal injury.
- Always use suitable mounting straps and
properly secure items to the tie-downs in
the luggage compartment to help prevent
items from shifting or flying forward as dan­
gerous missiles.
- When the rear seat backrest is folded down,
always use suitable mounting straps and
properly secure items to the tie-downs in
the luggage compartment to help prevent items from flying forward as dangerous
missiles into the passenger compartment.
- Never attach a child safety seat tether strap
to a tie-down.
Reporting Safety Defects
Applicable to U.S.A.
If you believe that your vehicle has a defect which could cause a
crash or could cause injury or
death, you should immediately in­
form the National Highway Traffic Safety Administration (NHTSA) in
addition to notifying Audi of
America, Inc.
If NHTSA receives similar com­
plaints, it may open an investiga­
tion, and if it finds that a safety
defects exists in a group of
vehicles, it may order a recall and ""'
243

® Mud and snow capability
"M/5" or "M+S" indicates the tire
is suitable for driving on mud and
snow. £ indicates a winter tire.
@ Composition of the tire cord
and materials
The number of plies indicates the
number of rubberized fabric lay­
ers in the tire . In general: the
more layers, the more weight a
tire can carry. Tire manufacturers must also specify the materials
used in the ti re . These inc lude
stee l, nylon, polyester and other
materials.
@ Maximum permitted load
This number indicates the maxi­
mum load in kilograms and
pounds that the tire can carry.
@ Un iform tire quality grade
standards for treadwear,
traction and temperature resistance
Treadwear, traction and tempera ­
ture ranges
¢page 333.
@ Running direction
T he arrows indicate the running
direction of unidirectional tires.
You must always follow the speci­
fied running direction
¢page 348.
Wheels
~ Maximum permitted tire
pressure
T his number indicates the maxi­
mum pressure to which a tire can
be inflated under normal operat ­
ing conditions .
Glossary of tire and loading
terminology
Accessory weight
means the combined weight (in
excess of those standard items
which may be replaced) of auto­ matic t ransmission, power steer ­
ing, power brakes, power win­
dows , powe r seats, radio, and
heater, to the extent tha t these
items are avai lab le as factory- in­
stalled equipment (whether in­
s t alled or not).
Aspect ratio
means the ratio of the height to
the w idth of the tire in percent.
Numbers of 55 or lower indicate a
low sidewall for improved steer­
ing response and better overall
handling on dry pavement .
Bead
means the part of the tire that is
made of steel wires, wrapped or
reinfo rced by ply cords and that is
shaped to fit the rim. ...
319

Wheel s
Bead separation
means a breakdown of the bond
between components in the bead .
Cord
means the strands forming the
plies in the tire.
Cold tire inflation pressure
means the tire pressure recom­
mended by the vehicle manufac­
turer for a tire of a designated
size that has not been driven for more than a couple of miles (kilo­
meters) at low speeds in the
three hour period before the tire
pressure is measured or adjusted.
Curb weight
means the weight of a motor ve­
hicle with standard equipment in­
cluding the maximum capacity of
fuel, oil, and coolant, air condi­
tioning and additional weight of
optional equipment.
E x tra load tire
means a tire designed to operate
at higher loads and at higher in­
flation pressures than the corre­ sponding standard tire . Extra load
tires may be identified as "XL",
"xl", "EXTRA LOAD", or "RF" on
the sidewal l.
320
Gross Axle Weight Rating
("GAWR ")
means the load-carrying capacity
of a single axle system, measured
at the tire -ground interfaces .
Gross Vehicle Weight Rating
(" GVWR ")
means the maximum total loaded
weight of the vehicle .
Groove
means the space between two ad­
jacent tread ribs .
Load rating (code )
means the maximum load that a
tire is rated to carry for a given in ­
flation pressure. You may not find
this information on all tires be­
cause it is not required by law.
Ma ximum load rating
means the load rating for a tire at
the maximum permissible infla­ tion pressure for that tire.
Ma ximum loaded vehicle
weight
means the sum of :
(a) Curb weight
(b) Accessory weight
(c) Vehicle capacity weight, and
(d) Production options we ight

Maximum (permissible )
inflat ion pressure
means the maximum cold infla­
tion pressure to wh ich a t ire may
be inflated . Also called "maxi ­
mum inflation pressure ."
Normal occupant weight
means 150 lbs . (68 kilograms)
times the numbe r of occupants
seated in the veh icle up to the to­
tal seating capacity of your vehi­
c le .
Occupant distribution
means distribution of occupants
in a vehicle .
Outer diameter
means the overall diameter of an
inflated new tire .
Overall width
means the linear dis ta n ce be­
tween the exteriors of the side ­
walls of an inflated tire, inc luding
e levations due to labeling, deco­
rations, or protect ive bands or
ribs.
Ply
means a layer of rubber-coated
parallel cords .
Wheels
Production options weight
means the combined weight of
those installed regular production
options weighing over 5 lbs. (2.3 kg) in excess of those standard
items which they replace, not pre­
viously considered in curb weight
or accessory weight, including heavy duty brakes, ride levelers,
roof rack , heavy d uty ba tte ry , and
special trim .
Radial ply tire
means a pneumatic tire in which
the ply cords that extend to the
beads are laid at substantia lly 90
degrees to the centerline of the
tread .
Recommended inflation
pressure
see ¢ page 320, Cold tire infla­
tion pressure .
Reinforced tire
means a tire designed to operate
at higher loads and at higher in ­
fl at ion pressures than the corre­
sponding standard tire. Rein­
forced tires may be identified as
"X L", "x l", "EXTRA LOA D", or "RF"
on the s idewa ll. ..,
321

Wheels
Rim
means a metal support for a tire
or a tire and tube assembly upon
which the t ire beads are seated .
Rim diameter
means nominal diameter of the
bead seat . If you change your
wh eel size, you will have to p ur­
chase new tires to match the new
rim d iameter .
Rim size designation
means rim diameter and w idth.
Rim width
means nomina l distance between
r im flanges .
Sidewall
means that portion of a t ire be­
twee n the tread and bead .
Speed rating (letter code)
means the speed at which a t ire is
designed to be driven for extend­
ed periods of ti me. The ratings
range from 93 mph (150 km/h)
to 186 mph (298 km/h)
¢ table
on page 318 .
You may not find
this information on all tires be­
cause it is not required by law.
The speed rating letter code,
wh ere applicable, is molded on
the tire sidewall and ind icates the
322
maximum permissible road
speeds
¢ A in Winter tires on
page 332 .
Tire pressure monitoring
system
means a system that detects
when one or mo re of a vehicle 's
tires a re underinflated and illumi ­
nates a low tire pressure war ning
telltale .
Tread
means that portion of a tire tha t
comes into contact wi th the road.
Tread separation
means pulling away of the tread
from the tire carcass .
Treadwear indicators (TWI)
means the projections wi thin the
pr inc ipal grooves designed to g ive
a visua l indication of the degrees
of wear of the t read . See
¢ page 326, Treadwear indicator
for mo re information on meas ur­
ing tire wear.
Uniform Tire Quality Grading
is a tire informa tion system devel ­
oped by the Unite d States Nation ­
a l Highway Traffic Safety Admin­
is tration (NHTSA) that is designed
to help buyers make re lat ive
..