traction control MERCEDES-BENZ E-Class SEDAN 2015 W212 Owner's Manual
[x] Cancel search | Manufacturer: MERCEDES-BENZ, Model Year: 2015, Model line: E-Class SEDAN, Model: MERCEDES-BENZ E-Class SEDAN 2015 W212Pages: 426, PDF Size: 8.27 MB
Page 11 of 426
Emergency locking ........................... 91
Emergency unlocking ....................... 91
Important safety note s.................... 89
Opening (from inside) ...................... 89
Drinking and driving ......................... 182
Drive program Automatic ...................................... 170
Display ........................................... 165
Display (DIRECT SELECT lever) ...... 166
Manual ........................................... 171
Manual (AMG vehicles) .................. 172
SETUP (on-board computer) .......... 248
Drive program selector ..................... 169
Driver's door see Doors
Driving abroad
Mercedes-Benz Service ................. 335
Symmetrical low beam .................. 128
Driving on flooded roads .................. 186
Driving safety systems ABS (Anti-lock Braking System) ....... 69
ADAPTIVE BRAK E............................. 78
Adaptive Brake Assist ...................... 73
BAS (Brake Assist System) .............. 70
BAS PLUS with Cross-Traffic
Assist ............................................... 70
COLLISION PREVENTION ASSIST
PLUS ................................................ 72
Distance warning function ............... 72
EBD (electronic brake force distri- bution) ............................................. 78
ESP ®
(Electronic Stability Pro-
gram) ............................................... 74
ETS/4ETS (Electronic Traction
System) ........................................... 75
Important safety information ........... 69
Overview .......................................... 69
PRE-SAFE ®
Brake ............................. 78
STEER CONTROL ............................. 80
Driving systems
360°camera .................................. 215
Active Blind Spot Assist ................. 224
Active Driving Assistance pack-
age ................................................. 224
Active Lane Keeping Assist ............ 227
Active Parking Assist ..................... 209
AIRMATIC ...................................... 202 AMG adaptive sport suspension
system ........................................... 203
ATTENTION ASSIST ........................ 219
Blind Spot Assist ............................ 220
Cruise control ................................ 187
Display message ............................ 268
DISTRONIC PLUS ........................... 189
DISTRONIC PLUS with Steering
Assist and Stop&Go Pilot ............... 198
HOLD function ............................... 200
Lane Keeping Assist ...................... 222
Lane Tracking package .................. 220
PARKTRONIC ................................. 206
RACE START (AMG vehicles) .......... 201
Rear view camera .......................... 214
Driving tips
AMG ceramic brakes ..................... 185
Automatic transmission ................. 168
Brakes ........................................... 183
Break-in period .............................. 156
Downhill gradient ........................... 183
Drinking and driving ....................... 182
Driving abroad ............................... 128
Driving in winter ............................. 186
Driving on flooded roads ................ 186
Driving on wet roads ...................... 185
Exhaust check ............................... 182
Fuel ................................................ 182
General .......................................... 181
Hydroplaning ................................. 185
Icy road surfaces ........................... 186
Limited braking efficiency on sal-
ted roads ....................................... 184
Snow chains .................................. 365
Symmetrical low beam .................. 128
Wet road surface ........................... 184
DVD video
Operating (on-board computer) ..... 239 E
EASY-ENTRY feature Activating/deactivating ................. 246
Function/note s............................. 121
EASY-EXIT feature
Crash-responsive ........................... 122
Function/note s............................. 121
Switching on/of f........................... 246 Index
9
Page 12 of 426
EASY-PACK cargo compartment
management system
........................ 304
EASY-PACK folding floor Important safety notes .................. 306
EASY-PACK folding luggage-com-
partment floor
Opening and closing ...................... 306
EASY-PACK load-securing kit
Components and storage .............. 304
Inserting the brackets into the
loading rail .................................... .305
EASY-PACK rear sill protector .......... 307
EASY-PACK trunk box ....................... 303
EBD (electronic brake force distri-
bution)
Display message ............................ 254
Function/notes ................................ 78
ECO display
Function/notes ............................ .182
On-board computer ....................... 236
ECO start/stop function
General information ....................... 161
Electronic Stability Program
see ESP ®
(Electronic Stability Program)
Emergency
Automatic measures after an acci-
dent ................................................. 61
Emergency release
Driver's door ................................... .91
Fuel filler fla p................................. 175
Trunk ............................................... 98
Vehicle ............................................. 91
Emergency spare wheel
General notes ................................ 404
Important safety notes .................. 404
Removing ....................................... 404
Storage location ............................ 404
Stowing .......................................... 405
Technical data ............................... 407
Emergency Tensioning Devices
Activation ......................................... 57
Emergency unlocking
Tailgate ............................................ 98
Emissions control
Service and warranty information .... 24 Engine
Check Engine warning lamp ........... 286
Display message ............................ 264
ECO start/stop function ................ 161
Engine number ............................... 411
Irregular running ............................ 164
Jump-starting ................................. 353
Starting problems .......................... 164
Starting the engine with the
SmartKey ....................................... 160
Starting with KEYLESS-GO ............. 160
Switching off .................................. 180
Tow-starting (vehicle) ..................... 358
Engine electronics
Problem (malfunction) ................... 164
Engine oil
Adding ........................................... 332
Additives ........................................ 416
Checking the oil level ..................... 331
Checking the oil level using the
dipstick .......................................... 332
Display message ............................ 266
Filling capacity ............................... 416
Notes about oil grade s................... 415
Notes on oil level/consumption .... 331
Temperature (on-board com-
puter) ............................................. 247
Viscosity ........................................ 416
ESP ®
(Electronic Stability Pro-
gram) AMG menu (on-board computer) ... 248
Characteristics ................................. 75
Deactivating/activating (AMG
vehicles) .......................................... 76
Deactivating/activating (except
AMG vehicles) ................................ 241
Deactivating/activating (notes;
except AMG vehicles) ...................... 76
Display message ............................ 252
ETS/4ETS ........................................ 75
Function/note s................................ 74
General notes .................................. 74
Important safety information ........... 75
Warning lamp ................................. 283
ETS/4ETS (Electronic Traction Sys-
tem) ...................................................... 75
Exhaust check ................................... 18210
Index
Page 77 of 426
ETS/4ETS (Electronic Traction System)
ETS traction control is part of ESP
®
. On vehi-
cles with 4MATIC, 4ETS is part of ESP ®
.
Traction control brakes the drive wheels indi-
vidually if they spin. This enables you to pull
away and accelerate on slippery surfaces, for
example if the road surface is slippery on one
side. In addition, more drive torque is trans-
ferred to the wheel or wheels with traction.
Traction control remains active, even if you
deactivate ESP ®
.
Important safety notes i
Observe the "Important safety notes" sec-
tion (Y page 69). G
WARNING
If ESP ®
is malfunctioning, ESP ®
is unable to
stabilize the vehicle. Additionally, further driv- ing safety systems are deactivated. This
increases the risk of skidding and an accident.
Drive on carefully. Have ESP ®
checked at a
qualified specialist workshop.
! Vehicles with 4MATIC: switch off the igni-
tion when the parking brake is being tested on a brake dynamometer.
Application of the brakes by ESP ®
may oth-
erwise destroy the brake system.
! Vehicles with 4MATIC: function or per-
formance tests may only be carried out on
a 2-axle dynamometer. Before you operate the vehicle on such a dynamometer, please
consult a qualified workshop. You could
otherwise damage the drive train or the
brake system.
! Vehicles with 4MATIC: function or per-
formance tests may only be carried out on
a 2-axle dynamometer. Before you operate the vehicle on such a dynamometer, please
consult a qualified workshop. You could
otherwise damage the drive train or the
brake system. Vehicles without 4MATIC: observe the notes
on ESP ®
(Y page 357) when towing the vehi-
cle with a raised rear axle.
ESP ®
is deactivated if the 00BBwarning lamp
in the instrument cluster lights up continu-
ously when the engine is running.
If the 00E5 warning lamp and the 00BBwarn-
ing lamp are lit continuously, ESP ®
is not
available due to a malfunction.
Observe the information on warning lamps
(Y page 283) and display messages which
may be shown in the instrument cluster
(Y page 252).
i Only use wheels with the recommended
tire sizes. Only then will ESP ®
function
properly.
Characteristics of ESP ® General information
If the
00E5 ESP warning lamp goes out before
beginning the journey, ESP ®
is automatically
active.
If ESP ®
intervenes, the 00E5ESP®
warning
lamp flashes in the instrument cluster.
If ESP ®
intervenes:
X Do not deactivate ESP ®
under any circum-
stances.
X Only depress the accelerator pedal as far as
necessary when pulling away.
X Adapt your driving style to suit the prevail-
ing road and weather conditions.
ECO start/stop function
The ECO start/stop function switches the
engine off automatically when the vehicle
stops moving. The engine starts automati-
cally when the driver wants to pull away again.
ESP ®
remains in its previously selected sta-
tus. Example: if ESP®
was deactivated before
the engine was switched off, ESP ®
remains
deactivated when the engine is switched on
again. Driving safety systems
75Safety Z
Page 78 of 426
Deactivating/activating ESP
®
(except
AMG vehicles) Important safety notes
You can select between the following sta-
tuses of ESP:
R ESP ®
is activated.
R ESP ®
is deactivated. G
WARNING
If you deactivate ESP ®
, ESP ®
no longer sta-
bilizes the vehicle. There is an increased risk
of skidding and an accident.
Only deactivate ESP ®
in the situations descri-
bed in the following.
! Avoid spinning the driven wheels for an
extended period with ESP ®
deactivated.
You could otherwise damage the drivetrain.
It may be best to deactivate ESP ®
in the fol-
lowing situations:
R when using snow chains
R in deep snow
R on sand or gravel
i Activate ESP ®
as soon as the situations
described above no longer apply. ESP ®
will
otherwise not be able to stabilize the vehi-
cle if the vehicle starts to skid or a wheel
starts to spin.
Deactivating/activating ESP ®
X To deactivate: (Ypage 241).
The 00BB ESP®
OFF warning lamp in the
instrument cluster lights up.
X To activate: (Ypage 241).
The 00BB ESP®
OFF warning lamp in the
instrument cluster goes out.
Characteristics when ESP ®
is deactivated
If ESP ®
is deactivated and one or more wheels
start to spin, the 00E5ESP®
warning lamp in
the instrument cluster flashes. In such situa-
tions, ESP ®
will not stabilize the vehicle. If you deactivate ESP
®
:
R ESP ®
no longer improves driving stability.
R engine torque is no longer limited and the
drive wheels are able to spin.
The spinning of the wheels results in a cut- ting action for better traction on loose sur-faces.
R traction control is still activated.
R ESP ®
still provides support when you
brake.
Deactivating/activating ESP ®
(AMG
vehicles) Important safety notes
You can select between the following sta-
tuses of ESP:
R ESP ®
is activated.
R SPORT handling mode is activated.
R ESP ®
is deactivated. G
WARNING
When SPORT handling mode is activated,
there is a greater risk of skidding and acci-
dents.
Only activate SPORT handling mode in the sit- uations described in the following. G
WARNING
If you deactivate ESP ®
, ESP ®
no longer sta-
bilizes the vehicle. There is an increased risk
of skidding and an accident.
Only deactivate ESP ®
in the situations descri-
bed in the following.
! Avoid spinning the driven wheels for an
extended period with ESP ®
deactivated.
You could otherwise damage the drivetrain.
It may be best to activate SPORT handling
mode in the following situations:
R when using snow chains
R in deep snow 76
Driving safety syste
msSafety
Page 79 of 426
R
on sand or gravel
R on designated roads when the vehicle's
own oversteering and understeering char-
acteristics are desired
Driving in SPORT handling mode or without
ESP ®
requires an extremely qualified and
experienced driver.
i Activate ESP ®
as soon as the situations
described above no longer apply. ESP ®
will
otherwise not be able to stabilize the vehi-
cle if the vehicle starts to skid or a wheel
starts to spin.
Deactivating/activating ESP ®X
To activate SPORT handling mode:
briefly press button 0043.
The 0074 SPORT handling mode warning
lamp in the instrument cluster lights up.
The SPORT handling mode SPORT handling mode message
appears in the multifunction display.
X To deactivate SPORT handling mode:
briefly press button 0043.
The 0074 SPORT handling mode warning
lamp in the instrument cluster goes out.
X To deactivate ESP ®
:press button 0043until
the 00BB ESP®
OFF warning lamp lights up
in the instrument cluster.
The 00E5 OFF
OFF message appears in the mul-
tifunction display.
X To activate ESP ®
:briefly press button 0043.
The 00BB ESP®
OFF warning lamp in the
instrument cluster goes out. The 00E5ONON
message appears in the multifunction dis-
play. Characteristics of activated SPORT han-
dling mode
If SPORT handling mode is activated and one
or more wheels start to spin, the 00E5ESP®
warning lamp in the instrument cluster
flashes. ESP ®
only stabilizes the vehicle to a
limited degree.
When SPORT handling mode is activated:
R ESP ®
only improves driving stability to a
limited degree.
R traction control is still activated.
R engine torque is only restricted to a limited
degree, and the drive wheels are able to
spin.
The spinning of the wheels results in a cut- ting action for better traction on loose sur-
faces.
R ESP ®
still provides support when you
brake.
Characteristics when ESP ®
is deactivated
If ESP ®
is deactivated and one or more wheels
start to spin, the 00E5ESP®
warning lamp in
the instrument cluster does not flash. In such
situations, ESP ®
will not stabilize the vehicle.
If you deactivate ESP ®
:
R ESP ®
no longer improves driving stability.
R engine torque is restricted to a limited
degree and the drive wheels are able to
spin.
The spinning of the wheels results in a cut-
ting action for better traction on loose sur-faces.
R traction control is still activated.
R PRE-SAFE ®
is no longer available, nor is it
activated if you brake firmly and ESP ®
intervenes.
R PRE-SAFE ®
Brake is no longer available, it
is also not activated if you brake firmly and
ESP ®
intervenes.
R ESP ®
still provides support when you
brake. Driving safety systems
77Safety Z
Page 189 of 426
Driving systems
Mercedes-Benz Intelligent Drive
Mercedes-Benz Intelligent Drive stands for
innovative driver assistance and safety sys-
tems which enhance comfort and support the
driver in critical situations. With these intelli-
gent co-ordinated systems Mercedes-Benz
has set a milestone 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
vehicle occupants and that of other road
users.
Further information on driving safety systems (Y page 69). Cruise control
General notes Cruise control maintains a constant road
speed for you. It brakes automatically in order
to avoid exceeding the set speed. On long and
steep downhill gradients, especially if the
vehicle is laden, you must shift to a lower gear in time. By doing so, you will make use of the
braking effect of the engine. This relieves the load on the brake system 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 If you fail to adapt your driving style, cruise
control can neither reduce the risk of an acci-
dent nor override the laws of physics. Cruise
control cannot take into account the road,
traffic and weather conditions. Cruise control is only an aid. You are responsible for the dis-
tance to the vehicle in front, for vehicle speed, for braking in good time and for staying in
your lane.
Do not use cruise control:
R in road and traffic conditions which do not
allow you to maintain a constant speed e.g.
in heavy traffic or on winding roads
R on slippery road surfaces. Braking or accel-
erating could cause the drive wheels to lose
traction and the vehicle could then skid
R when 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.
Cruise control lever 0043
To activate or increase speed
0044 To activate or reduce speed
0087 To deactivate cruise control
0085 To activate at the current speed/last
stored speed
When you activate cruise control, the stored
speed is shown in the multifunction display
for five seconds.
Activation conditions To activate cruise control, all of the following
activation conditions must be fulfilled:
R the parking brake must be released.
R you are driving faster than 20 mph
(30 km/h).
R ESP ®
must be active, but not intervening.
R the transmission must be in position D. Driving syste
ms
187Driving an d parking Z
Page 286 of 426
Problem
Possible causes/consequences and
0050
0050Solutions 00E5
The yellow ESP
®
warn-
ing lamp flashes while
the vehicle is in motion. ESP
®
or traction control has intervened because there is a risk of
skidding or at least one wheel has started to spin.
Cruise control or DISTRONIC PLUS is deactivated.
X When pulling away, only depress the accelerator pedal as far as
necessary.
X Ease off the accelerator pedal while the vehicle is in motion.
X Adapt your driving style to suit the road and weather conditions.
X Do not deactivate ESP ®
.
In rare cases (Y page 76) it may be best to deactivate ESP ®
.
Observe the important safety notes on ESP ®
(Y page 75). 00BB
The yellow ESP
®
OFF
warning lamp is lit while the engine is running. ESP
®
is deactivated.
G WARNING
If ESP ®
is switched off, ESP ®
is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
X Reactivate ESP ®
.
In rare cases (Y page 76), it may be best to deactivate ESP ®
.
Observe the important safety notes on ESP ®
(Y page 75).
X Adapt your driving style to suit the road and weather conditions.
If ESP ®
cannot be activated:
X Drive on carefully.
X Have ESP ®
checked at a qualified specialist workshop. 0074
AMG vehicles only:
The yellow SPORT han-
dling mode warning
lamp is lit while the
engine is running. SPORT handling mode is activated.
G WARNING
When SPORT handling mode is switched on, ESP ®
is unable to
stabilize the vehicle.
There is an increased risk of skidding and an accident.
X Only switch to SPORT handling mode in accordance with the
conditions described in the "Activating/deactivating SPORT
handling mode" section (Y page 76).284
Warning and indicator lamps in the instrument clusterOn-board computer and displays
Page 365 of 426
When parking your vehicle, make sure that
the tires do not get deformed by the curb or
other obstacles. If it is necessary to drive over
curbs, speed humps or similar elevations, try to do so slowly and at an obtuse angle. Oth-
erwise, the tires, particularly the sidewalls,
may be damaged. Regular checking of wheels and tires
G
WARNING
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.
Regularly check the wheels and tires of your
vehicle for damage at least once a month, as well as after driving off-road or on rough
roads. Damaged wheels can cause a loss of
tire pressure. Pay particular attention to dam-
age such as:
R cuts in the tires
R punctures
R tears in the tires
R bulges on tires
R deformation or severe corrosion on wheels
Regularly check the tire tread depth and the
condition of the tread across the whole width of the tire (Y page 363). If necessary, turn the
front wheels to full lock in order to inspect the
inner side of the tire surface.
All wheels must have a valve cap to protect
the valve against dirt and moisture. Do not
mount anything onto the valve other than the standard valve cap or other valve caps
approved by Mercedes-Benz for your vehicle.
Do not use any other valve caps or systems,
e.g. tire pressure monitoring systems.
Regularly check the pressure of all the tires
particularly prior to long trips. Adjust the tire pressure as necessary (Y page 366).
Observe the notes on the emergency spare
wheel (Y page 404). The service life of tires depends, among other
things, on the following factors:
R Driving style
R Tire pressure
R Distance covered Important safety notes on the tire
tread
G
WARNING
Insufficient tire tread will reduce tire traction.
The tire is no longer able to dissipate water.
This means that on wet road surfaces, the risk of hydroplaning increases, in particular where speed is not adapted to suit the driving con-
ditions. There is a risk of accident.
If the tire pressure is too high or too low, tires
may exhibit different levels of wear at differ-
ent locations on the tire tread. Thus, you
should regularly check the tread depth and
the condition of the tread across the entire
width of all tires.
Minimum tire tread depth for:
R Summer tires: 00CEin (3 mm)
R M+S tires: 00CFin (4 mm)
For safety reasons, replace the tires before
the legally prescribed limit for the minimum
tire tread depth is reached. Bar indicator
0043for tread wear is integrated
into the tire tread.
Treadwear indicators (TWI) are required by
law. Six indicators are positioned on the tire
tread. They are visible once a tread depth of Operation
363Wheels and tires Z
Page 366 of 426
approximately
00CDin(1.6 mm) has been
re ached. If this is the case, the tire is so worn
that it must be replaced. Selecting, mounting and replacing
tires
R Only mount tires and wheels of the same
type and make.
Exception: it is permissible to install a dif-
ferent type or make in the event of a flat
tire. Observe the "MOExtended tires (tires
with run-flat characteristics" section
(Y page 345).
R Only mount tires of the correct size onto
the wheels.
R Break in new tires at moderate speeds for
the first 60 miles (100 km). They only reach
their full performance after this distance.
R Do not drive with tires which have too little
tread depth, as this significantly reduces
the traction on wet roads (hydroplaning).
R Replace the tires after six years at the lat-
est, regardless of wear.
Observe the notes on the emergency spare
wheel (Y page 404). MOExtended tires (tires with run-flat
properties)
With MOExtended tires (tires with run flat
characteristics), you can continue to drive
your vehicle even if there is a total loss of
pressure in one or more tires.
MOExtended tires may only be used in con-
junction with an active tire pressure monitor
and only on wheels specifically tested by
Mercedes-Benz.
Notes on driving with MOExtended tires with
a flat tire (Y page 345).
i 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 may be obtained from a quali- fied specialist workshop. Winter operation
General notes
Have your vehicle winter-proofed at a quali-
fied specialist workshop at the onset of win-
ter.
Observe the notes in the "Changing a wheel"
section (Y page 384). Driving with summer tires
At temperatures below 45 ‡(+7 †), summer
tires lose elasticity and therefore traction and braking power. Change the tires on your vehi-cle to M+S tires. Using summer tires at very
cold temperatures could cause cracks to
form, thereby damaging the tires perma-
nently. Mercedes-Benz cannot accept
responsibility for this type of damage. G
WARNING
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
G
WARNING
M+S tires with a tire tread depth of less than
00CF 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 00CFin
(4 mm) must be replaced immediately.
At temperatures below 45 ‡(+7 †), use win-
ter tires or all-season tires. Both types of tire are identified by the M+S marking. 364
Winter operationWheels and tires
Page 379 of 426
Example:
R Treadwear grade: 200
R Traction grade: AA
R Temperature grade: A
All passenger car tires must conform to the
statutory safety requirements in addition to
these grades.
i The actual values for tires are vehicle-
specific 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, how-
ever, and may depart significantly from the
norm due to variations in driving habits, ser-
vice practices and differences in road char-
acteristics and climate conditions.
Traction G
WARNING
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
measured under controlled conditions on
specified government test surfaces of asphalt
and concrete. 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 surfa-
ces.
You should pay special attention to road con-
ditions when temperatures are around freez-
ing point.
Mercedes-Benz recommends a minimum
tread depth of 00CFin (4 mm) on all four winter
tires. Observe the legally required minimum
tire tread depth (Y page 363). Winter tires can
reduce the braking distance on snow-covered surfaces in comparison with summer tires.
The braking distance is still much further thanon surfaces that are not icy or covered with
snow. Take appropriate care when driving.
Further information on winter tires (M+S
tires) (Y page 364).
Temperature G
WARNING
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. They represent the tire's resistance to the generation of heat and its ability to dissi-pate heat when tested under controlled con-
ditions on a specified indoor laboratory test
wheel. Sustained 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. All about
wheels and tires
377Wheels and tires Z