2018 MERCEDES-BENZ S-CLASS CABRIOLET winter tires

The minimum tread depthfor summer tires is
â in (3 mm) and for winter tires ãin
(4 mm).
Six mar ks1 show where the bar indicators
(ar row ) are integrated into the tire tread. They
are visible once a tread dep thof appr oximately
á in (1.6 mm) has been reached.
Note s on snow chains
&
WARNING Risk of accident due toincor‐
re ct mounting of snow chains
If yo u ha vemounted snow chains tothe front
wheels, the snow chains may drag against
th eve hicle body or chassis components.
This could cause damage totheve hicle or
th e tires.
#Ne ver mount snow chains on the front
wheels.
#Only mount snow chains on there ar
wheels in pairs.
* NO
TEDama getothe wheel trim from
mounted snow chains
If snow ch ains are mounte dto steel wheels,
th e wheel trims can be damaged.
#Re mo vethe wheel trims of steel wheels
before mounting snow chains.
RSn ow chains are only pe rmissible for cer tain
wheel/tire combinations. You can obtain information about
this from a Mercedes-Benz
service cen ter.
RFo r saf etyre asons, only use snowchains that
ha ve been specifically appr ovedfo ryo ur
ve hicle byMercedes-Benz, or snow chains
with the same quality standard.
RIf snow chains are fitted, the maximum per‐
missible speed is 30 mph (50 km/h).
RVehicles with Active Parking Assis t:Do
no t use Parking Assist PARKTRONI Cwhen
sn ow ch ains ha vebeen ins talled.
RVe hicles with AIR BODY CONT ROL or
MAGIC BODY CONT ROL:If snow chains are
installed, only driv e atraised vehicle le vel.
% You can deactivate ESP
®to pull away
(→page 154). This allo ws the wheels to
spin, achieving an increased driving forc e.
Wheels and tires 363

The system checks the tire pressure and the tire
te mp erature of the tires ins talled on theve hicle
by means of a tire pressure sensor.
New tire pressure sensors, e.g. in winter tires,
are automatically taught-in during thefirs t jour‐
ney they are used.
If th ere is a subs tantial pressure loss or if the
tire temp erature is excessive, a warning will be
given:
Rvia display messages (→page 430)
Rvia theh warning lamp in the instrument
clus ter (→page 460)
It is the driver's responsibility toset the tire
pressure tothere commended cold tire pressure
suitable forth e operating situation. Set the tire
pressure for cold tires using a tire pressure
ga uge. Notethat the cor rect tire pressure forth e
cur rent operating situation must firs t be taught-
in to the tire pressure monitoring sy stem.
In most cases, the tire pressure monitoring sys‐
te m will auto matically update the new refere nce
va lues af teryo u ha vechanged the tire pressure.
Yo u can, ho wever,also update there fere nce val‐ ues
byrestarting the tire pressure monitoring
sy stem manually (
→page 369).
Sy stem limitations
The sy stem may be impaired or may n
ot function
in thefo llowing situations:
RIf th e tire pressure is set incor rectly
RIfth ere is a sudden pressure loss caused, for
ex ample, byafo re ign object penetrating the
tire.
RIf th ere is a malfunction caused byano ther
ra dio signal source
Make sure toobser vethefo llowing fur ther rela‐
te d subjec t:
RNotes on tire pressure (→page 364)
Checking the tire pressure with the tire pres‐
sure moni toring sy stem
Requ irements:
RThe ignition is switched on. On-board computer:
,Service.Tires
One of thefo llowing displa ysappears:
RCur rent tire pressure of ea chwheel:
RTire pressure will be displayed after driving a
few minutes
RTire Pressure Monitor Active: thete ach-in
process of the sy stem is not yet comple te.
The tire pressures are already being moni‐
to re d.
#Compare the tire pressure with there com‐
mended tire pressure forth e cur rent operat‐
ing status (
→page 365). Observ eth e no tes
on tire temp erature (→page 364).
% The values displa yed in the multifunction dis‐
play may deviate from those of the tire pres‐
sure gauge as they referto sea le vel.At high
altitudes, the tire pressure values indicated
by pressure gauges are higher than those
shown bythe on-board computer. In this
case, do not reduce the tire pressure.
368
Wheels and tires

IndexS peedrating
ZR...Y
1up to186mp h(3 00 km/h)
ZR...(..Y)
1ove r18 6mp h(3 00 km/h)
ZR
1ove r14 9mp h (240 km/h)
RSpecifying the speed rating as the "ZR" index
in tire code 4is optional for tires up to
18 6mp h(3 00 km/h).
RIfyo ur tire co de4 includes "ZR"andthere
is no speed rating 7,find out what the max‐
imum speed is from the tire manufacturer.
RIf load-bearing index 6and speed rating 7
are in brac kets, the maximum speed rating of
yo ur tire isabo ve186mp h (300 km/h). To
fi nd out the maximum speed, ask the tire
manufacturer. All-weather tires and winter tires
Inde
xS peedrating
Q M+S
2up to100mp h (160 km/h)
T M+S
2up to118mp h(190 km/h)
H M+S
2up to130mp h (2 10km/h)
V M+S
2up to149mp h (240 km/h)
Winter tires bear thei snowflake symbol
and fulfill therequ irements of theRu bber Manu‐
fa cturers Association (RMA) and theRu bber
Association of Canada (RAC) rega rding the tire
traction on sno w.
Load index 8
:RNo specification given: standard load (SL)
tire
R"XL" or "Extra Load": extra load tire or rein‐
fo rc ed tire
R"Light Load": light load tire
R"C", "D", "E": a load range that depends on
th e maximum load that the tire can car ryat a
cer tain pressure
Definition of termsfo r tires and loading
Ti re stru ctureand characteristics: describes
th e number of la yers or the number of rubber-
coated belts in the tire conta ct surface and the
tire wall. These are made of steel, nylon, poly‐
es ter and other materials.
Bar: metric unit for tire pressure .
14 .5038 pounds per square inch (psi) and
10 0 kilopascal (kPa) is the equivalent of one bar.
DOT (Department of Transport ation):DOT-
mar ked tires fulfill therequ irements of the
US Department of Transpor tatio n.
Av erage weight of theve hicle occupants: the
number of vehicle occupants for which th eve hi‐
cle is designed, multiplied by150 lb (68 kg).
1"ZR" stated in the tire code.2Or "M+S i"for winter tires
Wheels and tires 37
9

Observethefo llowing when selecting, ins talling
and replacing tires:
ROnly use tires and wheels of the same type
(summer tires, winter tires, MOEx tended
tires) and the same make.
ROnly ins tall wheels of the same size on one
axle (left and right).
It is only permissible toins tall a dif fere nt
wheel size in theeve nt of a flat tire in order
to drive tothe specialist workshop.
ROnly ins tall tires of the cor rect size onto the
wheels.
RVe hicles with a tire pressure monitoring
sy stem: all mounte d wheels must be equip‐
ped with functioning sensors forth e tire
pressure monitoring sy stem.
RAt temp eratures below 45 °F (7 °C), use win‐
te r tires or all-season tires mar ked M+S for
all wheels.
Wi nter tires bearing thei snowflake sym‐
bol in addition tothe M+S marking pr ovide
th e best possible grip in wintry road condi‐
tions.
RFo r M+S tires, only use tires with the same
tread.
RObser vethe maximum permissible speed for
th e M+S tires ins talled.
If th is is below theve hicle's maximum speed,
th is must be indicated in an appropriate label
in the driver's field of vision.
RRu n in new tires at moderate speeds forth e
fi rs t 60 miles (100 km).
RRe place the tires af ter six years at the latest,
re ga rdless of wear.
RWhen replacing with tires that do not fea‐
ture run-flat characteristics: vehicles with
MOExtended tires are not equipped with a
TIREFIT kit at thefa ctor y.Equip theve hicle
with a TIREFIT kit af terre placing with tires
th at do not feature run-flat characteristics,
e.g. winter tires.
Fo r more information on wheels and tires, con‐
ta ct a qualified specialist workshop.
Be sure toalso observ eth efo llowing fur ther
re lated subjects:
RNo tes on tire pressure (→page 364)
RTire and Loading Info rmation placard
(→page 370)
RTire size designation, load-beari ng capacity,
speed rating and load ind ex(→page 377)
RTire pressure table (→page 365)
Note s onrotating wheels
&
WARNING Risk of injury thro ugh dif fer‐
ent wheel sizes
Inter changing the front and rear wheels if the
wheels or tires ha vediffere nt dimensions
may se verely impair the driving characteris‐
tics.
The wheel brakes or wheel suspension com‐
ponents may also be damaged.
#Ro tate front and rear wheels only ifth e
wheels and tires are of the same dimen‐
sions.
384 Wheels and tires