winter tires MERCEDES-BENZ GLC COUPE 2017 X253 Owner's Manual

Maintenance and care......................300
Engine compartment ........................... 300
ASSYST PLUS ...................................... 304
Care ..................................................... 305
Breakdown assistance .....................313
Where will I find...? .............................. 313
Flat tire ................................................ 315
Battery (vehicle) .................................. 319
Jump-starting ....................................... 322
Towing and tow-starting ...................... 324
Fuses ...................................................3 27
Wheels and tires............................... 330
Important safety notes ........................ 330
Operation ............................................ 330
Winter operation .................................. 332
Tire pressure ....................................... 333
Loading the vehicle .............................. 340
All about wheels and tires ................... 343
Changing a wheel ................................ 350
Wheel/tire combination ......................3 54
Technical data................................... 356
Information regarding technical data ... 356
Vehicle electronics .............................. 356
Identification plates .............................3 57
Service products and filling capaci-
ties ...................................................... 358
Vehicle data ......................................... 364
Trailer tow hitch ................................... 365
Contents3

Warning lamp ................................. 256
Standing lamps
Display message ............................2 34
Switching on/off ........................... 109
Start button
Display message ............................ 251
Start/Stop button
Key positions ................................. 128
Starting the engine ........................ 129
Start/stop function
see ECO start/stop function
Starting (engine) ................................ 128
STEER CONTROL .................................. 74
Steering
Display message ............................ 249
Warning lamps ............................... 262
Steering Assist and Stop&Go Pilot .. 164
Steering Assist and Stop&Go Pilot
(DISTRONIC PLUS)
Display message ............................ 243
Steering assistant STEER CON-
TROL
see STEER CONTROL
Steering wheel
Adjusting (electrically) ................... 101
Adjusting (manually) ...................... 101
Button overview ............................... 36
Buttons (on-board computer) ......... 204
Cleaning ......................................... 311
EASY ENTRY/EXIT feature ............. 102
Important safety notes .................. 101
Storing settings (memory func-
tion) ............................................... 106
Steering wheel heating
Problem (malfunction) ................... 102
Switching on/off ........................... 101
Steering wheel paddle shifters ........ 140
Stop&Go Pilot and Steering Assist .. 164
Stopwatch (RACETIMER) ................... 220
Stowage areas ................................... 273
Stowage compartments
Armrest (under) ............................. 274
Center console .............................. 274
Cup holders ................................... 284
Door ............................................... 275
Eyeglasses compartment ............... 274
Glove box ....................................... 274 Important safety information ......... 273
Map pockets .................................. 275
Rear ............................................... 275
Stowage net ................................... 275
see Stowage areas
Stowage net ....................................... 275
Summer tires
In winter ........................................ 332
Sun visor ............................................ 285
Suspension settings
AIR BODY CONTROL ...................... 168
Suspe

nsion tuning
AMG sports suspension based on
AIR BODY CONTROL ...................... 169
SETUP (on-board computer,
Mercedes-AMG vehicles) ............... 219
Switching air-recirculation mode
on/off ................................................. 123
Switching on media mode
Via the device list .......................... 271
T
Tachometer ........................................ 204
Tail lamps
Display message ............................ 234
Tailgate
Display message ............................ 248
Emergency unlocking ....................... 88
HANDS-FREE ACCESS ..................... 86
Important safety notes .................... 83
Limiting the opening angle ............... 88
Obstruction detection ...................... 84
Opening dimensions ...................... 364
Opening/closing (automatically
from inside) ...................................... 87
Opening/closing (automatically
from outside) ................................... 84
Reversing feature ............................. 84
Tank content
Fuel gauge ....................................... 35
Technical data
Capacities ...................................... 358
Drawbar load (maximum) ............... 365
Information .................................... 356
Trailer loads ................................... 365
Vehicle data ................................... 364
20Index

Maximum load on a tire (defini-
tion) ............................................... 349
Maximum loaded vehicle weight
(definition) .....................................349
Maximum permissible tire pres-
sure (definition) .............................3 49
Maximum tire load ......................... 347
Maximum tire load (definition) ....... 349
MOExtended tires .......................... 332
Optional equipment weight (defi-
nition) ............................................ 350
PSI (pounds per square inch) (def-
inition) ...........................................3 49
Replacing ....................................... 350
Service life ..................................... 331
Sidewall (definition) ....................... 349
Snow chains .................................. 332
Speed rating (definition) ................ 349
Storing ...........................................3 51
Structure and characteristics
(definition) ..................................... 348
Summer tires in winter .................. 332
Temperature .................................. 344
TIN (Tire Identification Number)
(definition) ..................................... 350
Tire bead (definition) ......................3 49
Tire pressure (definition) ................ 349
Tire pressures (recommended) ...... 348
Tire size (data) ............................... 354
Tire size designation, load-bearing
capacity, speed rating .................... 345
Tire tread ....................................... 331
Tire tread (definition) ..................... 349
Total load limit (definition) ............. 350
Traction ......................................... 344
Traction (definition) ....................... 350
Tread wear ..................................... 344
Uniform Tire Quality Grading
Standards ...................................... 343
Uniform Tire Quality Grading
Standards (definition) .................... 348
Wear indicator (definition) ............. 350
Wheel and tire combination ........... 354
Wheel rim (defi nition) .................... 348
se

e Flat tire
Top Tether ............................................ 60
Topping up
DEF ................................................ 146 Touchpad
Changing the station/music
track .............................................. 266
Character suggestions ................... 265
Deleting characters ....................... 265
Entering a space ............................ 265
Entering characters ....................... 265
Gesture control .............................. 265
Handwriting recognition ................ 265
Operating the touchpad ................. 265
Overview ........................................ 265
Quick access for Audio .................. 266
Switching ....................................... 265
Switching input line ....................... 265
Tow-starting
Emergency engine starting ............ 327
Important safety notes .................. 324
Towing a trailer
Axle load, permissible .................... 365
Cleaning the trailer tow hitch ......... 310
Coupling up a trailer ...................... 199
Decoupling a trailer ....................... 201
Driving tips .................................... 198
ESP
®(Electronic Stability Pro-
gram) ............................................... 72
Important safety notes .................. 197
Installing the ball coupling ............. 199
Lights display message .................. 234
Power supply ................................. 201
Pulling away with a trailer .............. 130
Removing the ball coupling ............ 201
Trailer loads ................................... 365
Towing away
Important safety guidelines ........... 324
Installing the towing eye ................ 325
Notes for 4MATIC vehicles ............ 327
Removing the towing eye ............... 326
Transporting the vehicle ................ 326
With both axles on the ground ....... 326
Towing eye ......................................... 314
Traffic reports
see also Digital Operator's Man-
ual .................................................. 263
Traffic Sign Assist
Display message ............................ 242
Function/notes ............................. 187
Important safety notes .................. 188
Instrument cluster display ............. 188
22Index

VINSeat ............................................... 358
Type plate ...................................... 357
W
Warning and indicator lampsABS ................................................ 254
Air bags ......................................... 257
Brakes ........................................... 253
Coolant .......................................... 258
Distance warning ........................... 260
Engine diagnostics ......................... 258
ESP
®.............................................. 254
ESP®OFF ....................................... 256
Fuel tank ........................................ 258
General notes ................................ 251
Overview .......................................... 35
Parking brake ................................ 257
PASSENGER AIR BAG ...................... 43
Reserve fuel ................................... 258
Restraint system ............................ 257
Seat belt ........................................ 251
SPORT handling mode ................... 256
Steering ......................................... 262
Tire pressure monitor .................... 261
Warranty .............................................. 27
Washer fluid
Display message ............................ 249
Weather display (COMAND)
see also Digital Operator's Man-
ual .................................................. 263
Wheel and tire combinations
Tires ............................................... 354
Wheel bolt tightening torque ........... 354
Wheel chock ...................................... 351
Wheels
Changing a wheel .......................... 350
Checking ........................................ 330
Cleaning ......................................... 308
Important safety notes .................. 330
Information on driving .................... 330
Interchanging/changing ................ 350
Mounting a new wheel ................... 353
Mounting a wheel .......................... 351
Removing a wheel .......................... 353
Snow chains .................................. 332
Storing ........................................... 351 Tightening torque ........................... 354
Wheel size/tire size ....................... 354
Window curtain air bag
Display message ............................ 231
Operation ......................................... 49
Windows
see Side windows
Windshield
Defrosting ...................................... 121
Windshield washer fluid
see Windshield washer system
Windshield washer system
Adding washer fluid ....................... 304
Important safety notes .................. 363
Windshield wipers
Problem (malfunction) ................... 117
Replacing the wiper blades ............ 115
Switching on/off ........................... 114
Winter driving
Important sa fety note
s .................. 332
Slippery road surfaces ................... 156
Snow chains .................................. 332
Winter operation
Radiator cover ............................... 301
Summer tires ................................. 332
Winter tires
M+S tires ....................................... 332
Wiper blades
Cleaning ......................................... 309
Important safety notes .................. 115
Replacing ....................................... 115
Without changing gears
Display message ............................ 248
Wooden trim (cleaning instruc-
tions) .................................................. 311
Workshop
see Qualified specialist workshop
24Index

For safety reasons, Mercedes-Benz recom-
mends only installing the following brake disks
and brake pads/linings:
Rbrake disks that have been approved by
Mercedes-Benz
Rbrake pads/linings that have been approved
by Mercedes-Benz or that are of an equivalent
standard of quality
Other brake disks or brake pads/linings can
compromise the safety of your vehicle.
Always replace all brake disks and brake pads/
linings on an axle at the same time. Always
install new brake pads/linings when replacing
brake disks.
The vehicle is equipped with lightweight brake
disks to which the wheel assembly with rim and
threaded connection is matched.
The use of brake disks other than those
approved by Mercedes-Benz can change the
track width and is subject to approval, if appli-
cable.
Shock-type loads when handling the brake
discs, such as when changing wheels, can lead
to a reduction in comfort when driving with light-
weight brake discs. Avoid shock-type loads on
the lightweight brake disks, particularly on the
brake plate.
Mercedes-Benz recommends that you only use
brake fluid that has been specially approved for
your vehicle by Mercedes-Benz, or which corre-
sponds to an equivalent quality standard. Brake
fluid which has not been approved for
Mercedes-Benz vehicles or which is not of an
equivalent quality could affect your vehicle's
operating safety.
Driving on wet roads
Hydroplaning
If water has accumulated to a certain depth on
the road surface, there is a danger of hydro-
planing occurring, even if:
Ryou drive at low speeds
Rthe tires have adequate tread depth
For this reason, in the event of heavy rain or in
conditions in which hydroplaning may occur,
you must drive in the following manner:
Rlower your speed
Ravoid ruts
Ravoid sudden steering movements
Rbrake carefully
Driving on flooded roads
!Bear in mind that vehicles traveling in front
or in the opposite direction create waves. This
may cause the maximum permissible water
depth to be exceeded.
Failure to observe these notes may result in
damage to the engine, electrical systems and
transmission.
If you have to drive on stretches of road on which
water has collected, please bear in mind that:
Rin the case of standing water, the water level may be no higher than the lower edge of the
vehicle body
Ryou should drive no faster than walking pace
Winter driving
GWARNING
If you shift down on a slippery road surface in an attempt to increase the engine's braking
effect, the drive wheels could lose their grip.
There is an increased danger of skidding and
accidents.
Do not shift down for additional engine brak-
ing on a slippery road surface.
GDANGER
If the exhaust pipe is blocked or adequate
ventilation is not possible, poisonous gases
such as carbon monoxide (CO) may enter the vehicle. This is the case, e.g. if the vehicle
becomes trapped in snow. There is a risk of
fatal injury.
If you leave the engine or the auxiliary heating
running, make sure the exhaust pipe and area
around the vehicle are clear of snow. To
ensure an adequate supply of fresh air, open a
window on the side of the vehicle that is not
facing into the wind.
Have your vehicle winter-proofed at a qualified
specialist workshop at the onset of winter.
Drive particularly carefully on slippery road sur-
faces. Avoid sudden acceleration, steering and
156Driving tips
Driving and parking

braking maneuvers. Do not use the cruise con-
trol or DISTRONIC PLUS.
If the vehicle threatens to skid or cannot be
stopped when moving at low speed:
XShift the transmission to positioni.
The outside temperature indicator is not
designed to serve as an ice-warning device and is therefore unsuitable for that purpose.
Changes in the outside temperature are dis-
played after a short delay.
Indicated temperatures just above the freezing
point do not guarantee that the road surface is
free of ice. The road may still be icy, especially in
wooded areas or on bridges. The vehicle could
skid if you fail to adapt your driving style. Always
adapt your driving style and drive at a speed to
suit the prevailing weather conditions.
You should pay special attention to road condi-
tions when temperatures are around freezing
point.
For more information on driving with snow
chains, see (
Ypage 332).
For more information on driving with summer
tires, see (
Ypage 332).
Observe the notes in the "Winter operation" sec-
tion (
Ypage 332).
Driving systems
Mercedes-Benz Intelligent Drive
Mercedes-Benz Intelligent Drive stands for inno-
vative driver assistance and safety systems
which enhance comfort and support the driver in
critical situations. With these intelligent co-ordi- nated systems Mercedes-Benz has set a mile-
stone on the path towards autonomous driving.
Mercedes-Benz Intelligent Drive embraces all
elements of active and passive safety in one well
thought out system – for the safety of the vehi-
cle occupants and that of other road users.
Further information on driving safety systems
(
Ypage 63).
Cruise control
General notes
Cruise control maintains a constant road speed
for you. It brakes automatically in order to avoid exceeding the set speed. Change into a lower gear in good time on long and steep downhill
gradients. This is especially important if the
vehicle is laden or towing a trailer. By doing so,
you will make use of the braking effect of the
engine. This relieves the load on the brake sys-
tem and prevents the brakes from overheating
and wearing too quickly.
Use cruise control only if road and traffic con-
ditions make it appropriate to maintain a steady
speed for a prolonged period. You can store any
road speed above 20 mph (30 km/h).
Important safety notes
Cruise control can neither reduce the risk of an
accident if you fail to adapt your driving style nor override the laws of physics. Cruise control can-
not take into account the road, traffic and
weather conditions. Cruise control is only an
aid. You are responsible for maintaining a safe
distance to the vehicle in front, for vehicle
speed, for braking in good time and for staying in
lane.
Do not use cruise control:
Rin road and traffic conditions which do not
allow you to maintain a constant speed, e.g. in
heavy traffic or on winding roads
Ron slippery road surfaces. Braking or accel-
erating could cause the drive wheels to lose
traction and the vehicle could then skid
Rwhen there is poor visibility, e.g. due to fog,
heavy rain or snow
If there is a change of drivers, advise the new
driver of the speed stored.
iThe speed indicated in the speedometer
may differ slightly from the speed stored.
Cruise control lever
:Activates or increases speed
;Activates or reduces speed
Driving systems157
Driving and parking
Z

Sport mode
The firmer setting of the suspension tuning in
Sport mode ensures even better contact with
the road. Select this mode when employing a
sporty driving style, e.g. on winding country
roads.
XPress button:.
Indicator lamp =lights up. You have selected
Sport mode.
The AMG Suspension System SPORT
mes-
sage appears on the multifunction display.
Sport + mode
The very firm setting of the suspension setting in
Sport + mode ensures the best possible contact
with the road. Select this mode only when driv-
ing on race circuits.
If indicator lamps ;and =are off:
XPress button :twice.
Indicator lamps ;and =light up. You have
selected Sport + mode.
The AMG
SuspensionSystemSPORT +mes-
sage appears on the multifunction display.
If indicator lamp =lights up:
XPress button :once.
Second indicator lamp ;lights up. You have
selected Sport + mode.
The AMG
SuspensionSystemSPORT +mes-
sage appears on the multifunction display.
Comfort mode
In Comfort mode, the driving characteristics of
your vehicle are more comfortable. Select this
mode if you favor a more comfortable driving
style, but also when driving fast on straight
roads, e.g. highways.
XPress button :repeatedly until indicator
lamps ;and =go out.
You have selected Comfort mode.
The AMG
SuspensionSystemCOMFORTmes-
sage appears on the multifunction display.
4MATIC (permanent four-wheel drive)
4MATIC ensures permanent drive for all four
wheels. Together with ESP®, it improves the
traction of your vehicle whenever a drive wheel
spins due to insufficient grip.
If you fail to adapt your driving style or if you are inattentive, 4MATIC can neither reduce the risk
of an accident nor override the laws of physics.
4MATIC does not take into account
Rthe road and weather conditions
Rthe traffic situation
4MATIC is only an aid. You are responsible for
the distance to the vehicle in front, for vehicle
speed, for braking in good time and for staying in
your lane.
If a drive wheel spins due to insufficient grip:
ROnly depress the accelerator pedal as far as
necessary when pulling away.
RAccelerate less when driving.
!Never tow the vehicle with one axle raised.
This may damage the transfer case. Damage
of this sort is not covered by the Mercedes-
Benz Limited Warranty. All wheels must
remain either on the ground or be fully raised.
Observe the instructions for towing the vehi-
cle with all wheels in full contact with the
ground.
iIn wintry driving conditions, the maximum
effect of 4MATIC can only be achieved if you
use winter tires (M+S tires), with snow chains
if necessary.
PARKTRONIC
Important safety notes
PARKTRONIC is an electronic parking aid with
ultrasonic sensors. It monitors the area around
your vehicle using six sensors in the front
bumper and six sensors in the rear bumper.
PARKTRONIC indicates visually and audibly the
distance between your vehicle and an object.
170Driving systems
Driving and parking

XThoroughly hose down the vehicle with a gen-
tle jet of water.
XDo not point the water jet directly towards the
air inlet.
XUse plenty of water and rinse out the sponge
frequently.
XRinse the vehicle with clean water and dry
thoroughly with a chamois.
XDo not let the cleaning agent dry on the paint-work.
Carefully remove all deposits of road salt as
soon as possible when driving in winter.
Power washers
GWARNING
The water jet from a circular jet nozzle (dirt
blasters) can cause invisible exterior damage
to the tires or chassis components. Compo-
nents damaged in this way may fail unexpect-
edly. There is a risk of an accident.
Do not use power washers with circular jet
nozzles to clean the vehicle. Have damaged
tires or chassis components replaced imme-
diately.
!Always maintain a distance of at least
11.8 in (30 cm) between the vehicle and the
power washer nozzle. Information about the
correct distance is available from the equip-
ment manufacturer.
Move the power washer nozzle around when
cleaning your vehicle.
Do not aim directly at any of the following:
RTires
RDoor gaps, roof gaps, joints, etc.
RElectrical components
RBattery
RConnectors
RLamps
RSeals
RTrim
RVentilation slots
Damaged seals or electrical components can
lead to leaks or failures.
!Vehicles with decorative film: parts of your
vehicle are covered with a decorative film.
Maintain a distance of at least 27.5 in (70 cm) between the parts of the vehicle covered with
the film and the nozzle of the high pressure
cleaner.
Information about the correct distance is
available from the equipment manufacturer.
Move the power washer nozzle around when
cleaning your vehicle.
!If the SmartKey is within the rear detection
range of KEYLESS-GO, the following situa-
tions, for example, could lead to the uninten-
tional opening of the tailgate:
Rusing a car wash
Rusing a power washer
Make sure that the SmartKey is at least 3 m
away from the vehicle.
!If the SmartKey is within the rear detection
range of KEYLESS-GO, the following situa-
tions, for example, could lead to the uninten-
tional opening of the tailgate:
Rusing a car wash
Rusing a power washer
Make sure that the SmartKey is at least 10 ft
(3 m) away from the vehicle.
Cleaning the paintwork
!Do not affix:
Rstickers
Rfilms
Rmagnetic plates or similar items
to painted surfaces. You could otherwise
damage the paintwork.
Scratches, corrosive deposits, areas affected by
corrosion and damage caused by inadequate
care cannot always be completely repaired. In
such cases, visit a qualified specialist workshop.
XRemove dirt immediately, where possible,
while avoiding rubbing too hard.
XSoak insect remains with insect remover and
rinse off the treated areas afterwards.
XSoak bird droppings with water and rinse off
the treated areas afterwards.
XRemove coolant, brake fluid, tree resin, oils,
fuels and greases by rubbing gently with a
cloth soaked in petroleum ether or lighter
fluid.
XUse tar remover to remove tar stains.
XUse silicone remover to remove wax.
Care307
Maintenance and care
Z

MOExtended tires (tires with run-flat
properties)
With MOExtended tires (tires with run flat char-
acteristics), you can continue to drive your vehi-
cle even if there is a total loss of pressure in one
or more tires.
MOExtended tires may only be used in conjunc-
tion with an active tire pressure loss warning
system or with an active tire pressure monitor
and on wheels specifically tested by Mercedes-
Benz.
Notes on driving with MOExtended tires with a
flat tire (
Ypage 315).
Vehicles equipped with MOExtended tires are
not equipped with a TIREFIT kit at the factory. It
is therefore recommended that you additionally
equip your vehicle with a TIREFIT kit if you mount
tires that do not feature run-flat properties, e.g.
winter tires. A TIREFIT kit can be obtained from a qualified specialist workshop.
Winter operation
General notes
Have your vehicle winter-proofed at a qualified
specialist workshop at the onset of winter.
Observe the notes in the "Changing a wheel"
section (
Ypage 350).
Driving with summer tires
At temperatures below 45 ‡ (+7 †), summer
tires lose elasticity and therefore traction and
braking power. Change the tires on your vehicle
to M+S tires. Using summer tires at very cold
temperatures could cause cracks to form,
thereby damaging the tires permanently.
Mercedes-Benz cannot accept responsibility for
this type of damage.
GWARNING
Damaged tires can cause tire inflation pres-
sure loss. As a result, you could lose control of
your vehicle. There is a risk of accident.
Check the tires regularly for signs of damage
and replace any damaged tires immediately.
M+S tires
GWARNING
M+S tires with a tire tread depth of less than
ã in (4 mm) are not suitable for use in winter
and do not provide sufficient traction. There is
a risk of an accident.
M+S tires with a tread depth of less than ãin
(4 mm) must be replaced immediately.
At temperatures below 45 ‡(+7 †), use winter
tires or all-season tires. Both types of tire are
identified by the M+S marking.
Only winter tires bearing the isnowflake
symbol in addition to the M+S marking provide
the best possible grip in wintry road conditions.
Only these tires will allow driving safety systems
such as ABS and ESP
®to function optimally in
winter. These tires have been developed specif-
ically for driving in snow.
Use M+S tires of the same make and tread on all
wheels to maintain safe handling characteris-
tics.
Always observe the maximum permissible
speed specified for the M+S tires you have
mounted.
When you have mounted the M+S tires:
XCheck the tire pressures (Ypage 336).
XVehicles for Canada: restart the tire pres-
sure loss warning system (Ypage 337).
XRestart the tire pressure monitor
(Ypage 339).
Snow chains
GWARNING
If snow chains are installed to the front
wheels, they may drag against the vehicle
body or chassis components. This could
cause damage to the vehicle or the tires.
There is a risk of an accident.
To avoid hazardous situations:
Rnever install snow chains to the front
wheels
Ralways install snow chains in pairs to the
rear wheels.
332Winter operation
Wheels and tires

iThe actual values for tires are vehicle-spe-
cific and may deviate from the values in the
illustration.
Treadwear
The treadwear grade is a comparative rating
based on the wear rate of the tire when tested
under controlled conditions on a specified U.S.
government course. For example, a tire graded
150 would wear one and one-half times as well
on the government course as a tire graded 100.
The relative performance of tires depends upon
the actual conditions of their use, however, and
may depart significantly from the norm due to
variations in driving habits, service practices
and differences in road characteristics and cli-
mate.
Traction
GWARNING
The traction grade assigned to this tire is
based on straight-ahead braking traction
tests, and does not include acceleration, cor-
nering, hydroplaning, or peak traction char-
acteristics.
!Avoid wheelspin. This can lead to damage to
the drive train.
The traction grades – from highest to lowest –
are AA, A, B and C. Those grades represent the
tire's ability to stop on wet pavement as meas-
ured under controlled conditions on specified
government test surfaces of asphalt and con-
crete. A tire marked C may have poor traction
performance.
The safe speed on a wet, snow covered or icy
road is always lower than on dry road surfaces.
You should pay special attention to road condi-
tions when temperatures are around freezing
point.
Mercedes-Benz recommends a minimum tread
depth of ãin (4 mm) on all four winter tires.
Observe the legally required minimum tire tread
depth (
Ypage 331). Winter tires can reduce the
braking distance on snow-covered surfaces in
comparison with summer tires. The braking dis-
tance is still much further than on surfaces that
are not icy or covered with snow. Take appro-
priate care when driving. Further information on winter tires (M+S tires)
(
Ypage 332).
Temperature
GWARNING
The temperature grade for this tire is estab-
lished for a tire that is properly inflated and
not overloaded. Excessive speed, underinfla-
tion, or excessive loading, either separately or
in combination, can cause excessive heat
build-up and possible tire failure.
The temperature grades are A (the highest), B,
and C, representing the tire's resistance to the
generation of heat and its ability to dissipate
heat when tested under controlled conditions
on a specified indoor laboratory test wheel. Sus-
tained high temperature can cause the material
of the tire to degenerate and reduce tire life, and
excessive temperature can lead to sudden tire
failure. The grade C corresponds to a level of
performance which all passenger car tires must
meet under the Federal Motor Vehicle Safety
Standard No. 109. Grades B and A represent
higher levels of performance on the laboratory
test wheel than the minimum required by law.
344All about wheels and tires
Wheels and tires