ESP®can monitor and impr ovedriving stability
and traction in thefo llowing situations, within
ph ysical limits:
RWhen pulling away on a wet or slippe ryroad.
RWhen braking.
RIn stro ng sidewinds when you are driving
fast erthan 50 mph (80 km/h).
If th eve hicle deviates from the direction desired
by the driver, ESP
®can stabilize theve hicle by
inter vening in thefo llowing ways:
ROne or more wheels are braked.
RThe engine output is adap ted according to
th e situation.
ESP
®is deactivated if the ESP®OFF å warn‐
ing lamp lights up continuously in the instrument
clus ter:
RDriving stability will no longe r be improved.
RCrosswind Assist is no longer active.
RThe drive wheels could spin.
RETS/4ETS traction control is still active.
% When ESP
®is deactivated, you are still assis‐
te dby ESP®when braking.
ESP
®is inter vening if the ESP®÷ warning
lamp flashes in the instrument clus ter:
RDo not deacti vate ESP®.
ROnly depress the accelera tor pedal as far as
is necessar y.
RAdapt your drivin gst yle to suit the cur rent
ro ad and weather conditions.
Deactivate ESP
®in thefo llowing situations to
impr ovetraction:
RWhen using snow chains
RIn deep snow
ROn sand or gr avel.
% Spinning the wheels results in a cutting
action which pr ovides better grip.
If th e ESP
®÷ warning lamp lights up continu‐
ousl y,ESP®is not available due toa malfunction. Observ
eth efo llowing information:
RWa rning and indicator lamps (→page 501)
RDisplay messages (→page 457)
ETS/4ETS (Electronic Traction Sy stem)
ETS/4ETS traction control is pa rtof ESP
®and
makes it possible topull away or accelerate on a
slippery sur face.
ETS/4ETS can impr oveth eve hicle's traction by
inter vening in thefo llowing ways:
RThe drive wheels are braked individually if
they spin.
RMore drive torque is transferred tothe wheel
or wheels with traction.
Influence of drive prog rams on ESP
®
The drive programs enable ESP®to adapt todif‐
fe re nt we ather and road conditions as well as
th e driver's prefer red driving style. You can
select the drive programs using theDY NA MIC
SELECT switch (
→page 173).
19 0
Driving and pa rking
Cruise cont rol is operated using the cor respond‐
ing steering wheel buttons. You can store any
ro ad speed abo ve15 mp h (20 km/h).
If yo ufa ilto adapt your drivin gst yle, cruise con‐
trol can neither reduce therisk of an accident
nor override the la wsof ph ysics. It cannot take
into account road, weather or traf fic conditions.
Cruise control is only an aid. You are responsible
fo rth e dis tance totheve hicle in front, forve hi‐
cle speed, for braking in good time and forst ay ‐
ing in lane.
Displa ysinthe multifunction display
The status of cruise control and thestored
speed are shown in the multifunction displa y.
1Cruise control is selecte d
2Speed is sa ved, cruise control is deactivated
3Speed is sa ved, cruise control is activated
% The segments between thestored speed and
th e end of the segment display light up in
th e speedome ter.
Sy stem limitations
Cruise control may be unable tomaintain the
st ored speed on uphill gradients. The stored
speed is resumed when the gradient evens out.
Change into a lo werge ar in good time on long
and steep downhill gradients. Take particular
no te ofthis when driving a laden vehicle. By doing so,
youwill make use of the braking ef fect
of the engine. This relie vesth e load on the brake
sy stem and pr events the brakes from overheat‐
ing and wearing tooqu ickl y.
Do not use cruise control in thefo llowing situa‐
tions:
RIn traf fic situations whi chrequ ire frequent
ch anges of speed, e.g. in heavy traf fic, on
winding roads
ROn slippery roads. Accelerating can cause
th e drive wheels tolose traction and the
ve hicle could then skid
RWhen visibility is poor
Operating cruise control
& WARNING Risk of accident due tostored
speed
If yo u call up thestored speed and this is
lo we rth an your cur rent speed, theve hicle
decelerates.
#Ta ke into account the tra ffic situation
before calling up thestored speed.
Driving and parking 19
7
Active Di stance Assist DI STRONIC
Function of Active Di stance Assist
DI STRO NIC
Active Dis tance Assist DISTRONIC maintains the
set speed on free-flowing roads. If vehicles
ahead are de tected, the set dis tance is main‐
ta ined, if necessary until theve hicle comes toa
halt. The vehicle accelerates or brakes depend‐
ing on the dis tance totheve hicle in front and
th e set speed. Speed (in thera nge between
15 mp h(2 0 km/h) and 130mp h(210 km/h))
and the dis tance totheve hicle ahead are set
and sa ved on thesteering wheel. Other
features of Active Dis tance Assist
DISTRONIC:
RAd justs the driving style depending on the
selected drive program (fuel-saving, comfort‐
able or dynamic) (
→page 172)
RRe sponds in urban speed ranges tostation‐
ary vehicles (e xcept bicycles, mo torcyc les
and pedestrians) if conditions are suf ficient
to enable de tection.
RInitiates rapid acceleration tothestored
speed, if the turn signal indicator is switched
on tochange totheov ertak ing lane.
RTake s one-sided overtaking restrictions into
account on free ways or on multi-lane roads
with separate car riag ewa ys.
Ve hicles with Active Parking Assis t:ifth eve hicle
has been braked toast andstill on multi-lane,
separate car riag ewa ysby Active Dis tance Assist
DISTRONIC, it can au tomatically follow theve hi‐
cle in front driving off again, within 30 seconds.
If a crit
ical situation is de tected when driving off,
a visual and acoustic warning is given indicating
th at the driver must now take control of theve hi‐
cle. The vehicle is not accelerated any fur ther. Ac
tive Dis tance Assist DISTRONIC is only an aid.
The driver is responsible forth e dis tance tothe
ve hicle in front, forve hicle speed and for braking
in good time.
Sy stem limitations
The sy stem may be impaired or may not function
in thefo llowing ins tances, forex ample:
RIn snow ,ra in, fog, heavy spr ay, if there is
gl are, in direct sunlight or in greatly varying
ambient light.
RThe windshield in the area of the camera is
dirty, fogged up, damaged or co vered.
RIfth era dar sensors are dirty or co vered.
ROn slippery roads, braking or accelerating
can cause the drive wheels tolose traction
and theve hicle could then skid.
RIn parking garage s or on roads with steep
uphill or downhill gradients.
Do not use Active Dis tance Assist DISTRONIC in
th ese situations.
Driving and parking 19
9
Tire labeling
Overview of tire labeling
1Uni form Ti reQuality Grading Standard
(→page 425)
2DO T,Tire Identification Number
(→page 426)
3Maximum tire load (→page 427)
4Maximum tire pressure (→page 428)
5Manufacturer
6Characteristics ofthe tire (→page 428)
7Tire size designation, load-beari ng capacity,
speed rating and load ind ex(→page 428)
8Tire name
% The da tashown in the image is example
data.
Ti re Quality Grading
In accordance with the US Department of Trans‐
por tation's "Unifo rm TireQuality Grading Stand‐
ards", tire manufacturers are requ ired tograde
th eir tires on the basis of thefo llowing thre e per‐
fo rm ance factors:1Tread weargrade
2Traction grade
3Te mp erature grade
% The data shown in the image is example
data.
% The classification is not legally stipulated for
Canada, but it is general lystated.
Tr ead weargrade
The tread wear grade is a comparative rating
based on thewe arrate ofthe tire when tested
under controlled conditions on a specified test
track of the US Department of Transpor tation.
Fo rex ample, a tire graded 150wo uld wear one
Wheels and tires 425
and one-half times aswell on the go vernment
te st track as a tire graded 100.
The relative per form ance of tires depends upon
th e actual conditions of their use, ho wever,and
may depart significantly from the norm due to
va riations in driving habits, service practices and
dif fere nces in road characteristics and climate
conditions.
Tr action grade
&
DANG ER Risk of accident due toinade‐
qu ate traction
The traction grade assigned tothis tire is
based on stra ight-ahead braking traction
te sts, and does not include either accelera‐
tion, cornering, hydroplaning or peak traction
ch aracteristics.
#Alw ays adapt your drivin gst yle and
drive at a speed tosuit the pr evailing
traf fic and weather conditions.
* NO
TEDama getothe driv etra in from
wheelspin
#Av oid wheelspin.
The traction grades – from highest tolowest –
are AA, A,B and C. Those grades represent the
tire's ability tostop on wet pa vement as meas‐
ured under controlled conditions on specified
go vernment test sur faces made of asphalt and
concr ete.
Te mp erature grade
&
WARNING Risk of accident from tire
ove rheating and tire failure
The temp erature grade forth is tire is es tab‐
lished for a tire that is proper ly 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.
#Obser vethere commended tire pres‐
sure s and regularly check the tire pres‐
sure of all tires including the spare
wheel.
#Ad just the tire pressure as necessar y.
Thetemp erature grades are A (the highest), B
and C. They represent the tire's resis tance tothe
ge neration of heat and its ability todissipate
heat when tested under controlled conditions on
a specified indoor laboratory test wheel. Sus‐
ta ined high temp erature can cause the material
of the tire todegenerate and reduce tire life, and
exc essive temp erature can lead tosudden tire
fa ilure. Grade C cor responds toa le vel of per‐
fo rm ance which all passenger car tires must
meet under therequ irements of the US Depart‐
ment of Transpor tation.
DO T,Tire Identification Number (TIN)
US tire regulations stipulate that eve rytire man‐
ufactu rer or retreader must imprint a TIN in or
on the side wall of each tire produced.
426
Wheels and tires
these are ins talled on theve hicle, but does not
include passengers or luggage.
Maximum tire load: the maximum tire load is
th e maximum permissible weight in kilog rams or
lbs for which a tire is appr oved.
Maximum permissible tire pressure: maxi‐
mum permissible tire pressure for one tire.
Maximum load on one tire: maximum load on
one tire. This is calculated bydividing the maxi‐
mum axle load of one axle bytwo.
PSI (pounds per square in ch):standard unit of
measurement for tire pressure .
Aspect ratio: ratio between tire height and tire
width in pe rcent.
Ti re pressure: pressure inside the tire applying
an outward forc eto eve rysquare inch of the tire.
The tire pressure is specified in pounds per
square inch (psi), in kilopascals (kPa) or in bar.
The tire pressure should only be cor rected when
th e tires are cold.
Cold tire pressure: the tires are cold when the
ve hicle has been par kedfo r at least 3 hours without direct sunlight on
the tires or theve hicle
has been driven for less than 1 mile (1.6 km).
Ti re contact sur face: the part of the tire that
comes into con tact wi th thero ad.
Ti re bead: the purpose of the tire bead is to
ensure that the tire sits securely on the wheel
ri m. There are se veral wire cores in the tire bead
to pr
eve ntthe t
ire fromchanging length on the
wheel rim.
Side wall:the part of the tire between the tread
and the tire bead.
We ight of optional equipment: the combined
we ight of the optional equipment weighing more
th an there placed standard parts and more than
5 lbs (2.3 kg).This optional equipment, such as
high-per form ance brakes, le vel control sy stem, a
ro of luggage rack or high-per form ance batte ries,
is not included in the curb weight and thewe ight
of the accessories.
TIN (Tire Identification Number): a unique
identification number which can be used bya
tire manufactu rerto identify tires, forex ample,
in a product recall, and thus identify the pur‐
ch asers. The TIN is made up of the manufactur‐ er's identity code, tire size, tire type code and
th
e manufacturing date.
Load-bearing index: the load-bearing index is a
code that con tains the maximum load-bearing
capacity of a tire.
Tr action: traction is the grip resulting from fric‐
tion between the tires and thero ad sur face.
We ar indicator: narrow bars (tread wear bars)
th at are distributed overth e tire conta ct surface.
If th e tire tread is le vel with the bars, thewe ar
limit of 1/ 16in (1.6 mm) has been reached.
Distribution of vehicle occupants: distribution
of vehicle occupants ov
er design
ated seat posi‐
tions in a vehicle.
Maximum permissible pa yload weight: nomi‐
nal load and luggage load plus 150 lb (68 kg)
multiplied bythe number of seats in theve hicle.
432
Wheels and tires