MERCEDES-BENZ S-CLASS CABRIOLET 2019 Owner's Manual

and one-half times as
well 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 driving style and
drive at a speed tosuit the pr evailing
traf fic and weather conditions. *
NO
TEDama getothe driv etra in from
wheelspin #
Avoid 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‐
su res and regularly check the tire pres‐ sure of all tires including
the spare
wheel. #
Adjust the tire pressure as necessar y. The
temp 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 mu stimprint a TIN in or
on the side wall of each tire produced. Wheels and tires
389

%
The data shown in the image is example
data.
The TIN is a unique identification number to
identify tires and comprises thefo llowing:
R DOT (Department of Transpo rtation): tire
symbol mar ks1 indicating that the tire
complies with therequ irements of the US
Department of Transpor tation.
R Manufacturer identi fication code: manu‐
fa cturer identification code 2contains
de tails of the tire manufacturer. New tires
ha ve a code with two symbols. Retreaded
tires ha vea code with four symbols. Further
information on retreaded tires (→ page 396). R
Tire size: identifier 3describes the tire
size.
R Tire type code: tire type code 4can be
used bythe manufacturer as a code to
describe specific characteristics of the tire.
R Manufacturing date: manufacturing date
5 prov ides information about the age of a
tire. The 1st and 2nd positions represent the
calendar week and the 3rd and 4th positions
st ate theye ar of manufacture (e.g. "3208"
re presents the 32nd week of 2008). Information on
the maximum tire load %
The data shown in the image is example
data.
Maximum tire load 1isthe maximum permissi‐
ble weight for which the tire is appr oved.
Do not overload the tires by exceeding the speci‐
fi ed load limit. The maximum permissible load
can be found on theve hicle's Tire and Loading
In fo rm ation placard on the B-pillar on the driv‐
er's side (→ page 384). Specifications
for maximum tire pressure %
The da tashown in the image is example
data. 390
Wheels and tires

Ne
verexc eed maximum tire pressure 1speci‐
fi ed forth e tire. Information on tire
characteristics %
The data shown in the image is example
data.
This information desc ribes the type of tire cord
and the number of la yers in side wall1 and
under tire tread 2. Ti
re size designation, load-bearing capacity,
speed rating and load index &
WARNING Risk of inju rythro ugh exceed‐
ing the specified tire load rating or the
permissible speed rating
Exceeding the specified tire load rating or
th e permissible speed rating may lead totire
dama geand tothe tires bur sting. #
Therefore, only use tire types and sizes
appr ovedfo ryo ur vehicle model. #
Obser vethe tire load rating and speed
ra ting requ ired foryo ur vehicle. 1
Preceding letter
2 Nominal tire width in millime ters
3 Aspect ratio in %
4 Tire code
5 Rim diame ter
6 Load-bearing index
7 Speed rating
8 Load ind ex
% The data shown in the image is example
data.
In fo rm ation about reading tire data can be
obtained from any qualified specialist workshop. Wheels and tires
391

Preceding letter
1
1:
R Without: passenger vehicle tires according to
European manufactu ring standards.
R "P": passenger vehicle tires according toUS
manufacturing standards.
R "LT": light truck tires according toUS manu‐
fa cturing standards.
R "T": compact emer gency spa rewheels with
high tire pressure that are on ly designed for
te mp orary use in an emer gency.
Aspect ratio 3
3:
Ra tio between tire height and tire width in per‐
cent (ti reheight divided bytire width).
Tire code 4
4(tire type):
R "R" radial tire
R "D": bias ply tire
R "B": bias belted tires
R "ZR": radial tire with a maximum speed abo ve
14 9mp h (240 km/h) (optional) Rim diame
ter5
5:
The diam eter of the bead seat (not the diame ter
of therim flange). The rim diame ter is specified
in inches (in).
Load-bearing index 6 6:
Numerical code that specifies the maximum
load-bearing capacity of a tire (e.g. "91" cor re‐
sponds to1356 lbs (6 15kg)).
The load-bearing capacity of the tire must be at
least half the permissible axle load of your vehi‐
cle. Do not overload the tires byexc eeding the
specified load limit.
See also:
R Maximum permissible load on theTire and
Loading In form ation placard (→ page 384)
R Maximum tire load (→ page 390)
R Load ind ex
Speed rating 7 7:
Specifies the appr oved maximum speed of the
tire. %
An electronic speed limi ter pr events your
ve hicle from exceeding a speed of 130mph
(2 10 km/h).
Ma kesure that your tires ha vetherequ ired
speed rating. You can obtain information on the
re qu ired speed rating from an au thorized
Mercedes-Benz Center.
Summer tires Inde
xS peedrating
Qu pto 100mp h (160 km/h)
Ru pto 106mp h (170 km/h)
Su pto 112mp h (1 80 km/h)
Tu pto 118mp h (190 km/h)
Hu pto 130mp h (2 10km/h)
Vu pto 149mp h (2 40 km/h)
Wu pto 168mp h (270 km/h)
Yu pto 186mp h (3 00 km/h) 392
Wheels and tires

Inde
xS peedrating
ZR...Y 1
upto186mp h (3 00 km/h)
ZR...(..Y) 1
over18 6mp h (3 00 km/h)
ZR 1
over14 9mp h (240 km/h) R
Specifying the speed rating as the "ZR" index
in tire code 4is optional for tires up to
18 6mp h (3 00 km/h).
R Ifyo ur tire code 4includes "ZR" and there
is no speed rating 7,find out what the max‐
imum speed is from the tire manufacturer.
R If load-bearing index 6and speed rating 7
are in brac kets, the maximum speed rating of
yo ur tire is abo 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 2
upto100mp h (160 km/h)
T M+S 2
upto118mp h (1 90 km/h)
H M+S 2
upto130mp h (2 10km/h)
V M+S 2
upto149mp h (240 km/h) Wi
nter tires bear the004D 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
8:
R No 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 pressu re.
14 .5038 pounds per square inch (psi) and
10 0 kilopascal (kPa) is the equivalent of one bar.
DOT (Department of Transpo rtation): 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.
2 Or "M+S 004D"for winter tires Wheels and tires
393

Un
iform Tire Quality Grading Standards: a
uniform standard tograde thequ ality of tires
with rega rd totread qualit y,tire traction and
te mp erature characteristics. The quality grading
assessment is made bythe manufacturer follow‐
ing specifications from theU. S. go vernment. The
qu ality grade of a tire is imprinted on the side
wa ll of the tire.
Re commended tire pressu re:there commen‐
ded tire pressure is the tire pressure specified
fo rth e tires mounted totheve hicle at thefa c‐
to ry.
The tire and information table con tains there c‐
ommended tire pressures for cold tires, the max‐
imum permissible load and the maximum per‐
missible vehicle speed.
The tire pressure table con tains there commen‐
ded tire pressures for cold tires under various
operating conditions, i.e. loading and/or speed
of theve hicle.
Increased vehicle weight due tooptional
equipment: the combined weight of all standard
and optional equipment available forth eve hicle, re
ga rdless of whe ther it is actually ins talled on
th eve hicle or not.
Rim: the part of the wheel on which the tire is
ins talled.
GA WR (Gross Axle Weight Rating): the GAWR
is the maximum permissible axle load. The
actual load on an axle must ne verexc eed the
gross axleweight rating. The gross axle weight
ra ting can be found on theve hicle identification
plate on the B‑pillar on the driver's side.
Speed rating: the speed rating is pa rtof the tire
identification. It specifies the speed range for
which a tire is appr oved.
GV W (Gross Vehicle Weight): the gross vehicle
we ight comprises thewe ight of theve hicle
including fuel, tools, the spare wheel, accesso‐
ri es ins talled, occupants, luggage and the trailer
dr aw bar nose weight, if applicable. The gross
ve hicle weight must not exceed the gross vehicle
we ight rating GVWR as specified on theve hicle
identification plate on the B‑pillar on the driver's
side.
GV WR (Gross Vehicle Weight Rating): the
GV WR is the maximum permitted gross weight of
the fully laden vehicle (weight of theve hicle
including all accessories, occupants, fuel, lug‐
ga ge and the trailer dr awbar nose weight if appli‐
cable). The grossvehicle weight rating is speci‐
fi ed on theve hicle identification plate on the
B‑pillar on the driver's side.
Maximum weight of the laden vehicle: the
maximum weight is the sum of the curb weight
of theve hicle, thewe ight of the accessories, the
maximum load and thewe ight of optional equip‐
ment ins talled at thefa ctor y.
Kilopascal (kPa): metric unitfor tire pressu re.
6.9 kPa cor responds to1 psi. Ano ther unit for
tire pressu reis bar. 100 kilopascal (kPa) equals
1 bar.
Load index: in additiontothe load-bearing
index, the load index may also be imprinted on
th e side wall of the tire. This specifies the load-
bearing capacity of the tire more precisel y.
Curb weight: thewe ight of a vehicle with stand‐
ard equipment including the maximum capacity
of fuel, oil and coolant. It also includes the air
conditioning sy stem and optional equipment if 394
Wheels and tires

th
ese 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 pressu re.
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 preve ntthe tire from changing 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 bat teries,
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 by a
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 over designated 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. Wheels and tires
395

Changing a wheel
Note
s on selecting, installing and replacing
tires Mercedes
-AMG vehicles: observeth e no tes in
th e Supplement. Otherwise, you may not recog‐
nize dangers.
Yo u can ask for information rega rding permit ted
wheel/tire combinations at an authorized
Mercedes-Benz Center. &
WARNING Risk of accident due toincor‐
re ct dimensions of wheels and tires
If wheels and tires of the wrong size are
ins talled, the wheel brakes or wheel suspen‐
sion components may be damaged. #
Alw aysre place wheels and tires with
th ose that fulfill the specifications of
th e original part.
When replacing wheels, make sure tofit the
cor rect:
R Designation R
Model
When replacing tires, make sure toins tallthe
cor rect:
R Designation
R Manufactu rer
R Model &
WARNING Risk of inju rythro ugh exceed‐
ing the specified tire load rating or the
permissible speed rating
Exceeding the specified tire load rating or
th e permissible speed rating may lead totire
dama geand tothe tires bur sting. #
Therefore, only use tire types and sizes
appr ovedfo ryo ur vehicle model. #
Obser vethe tire load rating and speed
ra ting requ ired foryo ur vehicle. *
NO
TEVehicle and tire damage thro ugh
tire types and sizes that ha venot been
appr oved Fo
r saf etyre asons, on lyuse tires, wheels
and accessories which ha vebeen specially
appr ovedby Mercedes-Benz foryo ur vehicle.
These tires are specially adap tedto the con‐
trol sy stems, such as ABS, ESP ®
and
4MATIC, and mar ked as follo ws:
R MO = Mercedes-Benz Original
R MOE = Mercedes-Benz Original Extended
(run-flat tire only for cer tain wheels)
R MO1 = Mercedes-Benz Original (only cer‐
tain AMG tires)
Cer tain characteristics, such as handling,
ve hicle noise emissions, fuel consum ption,
et c. may otherwise be adversely af fected.
Fu rthermore, other tire sizes could result in
th e tires rubbing against the body and axle
components when loaded. This could result
in damage tothe tire or theve hicle. 396
Wheels and tires

Only use tires, wheels and accessories
that
ha ve been checked and recommended by
Mercedes-Benz. *
NO
TERisk todriving saf ety from retrea‐
ded tires Re
treaded tires are nei ther tested nor recom‐
mended byMercedes-Benz, since pr evious
damage cannot alw ays be de tected on
re treaded tires.
Fo rth is reason driving saf ety cannot be guar‐
anteed. #
Do not use used ti res if you ha veno
information about their pr evious usage. *
NO
TEPossible damage towheels or tires
when driving over obs tacles Large wheels ha
vea lo wer tire section width.
The lo werth e tire section width, the greater
is therisk of damage towheels or tires when
driving over obs tacles. #
Avoid obs tacles or drive pa rticular ly
carefully. *
NO
TEDama getoelectronic component
parts from the use of tire-mounting tools Ve
hicles with a tire pressure monitoring
sy stem: Electronic component parts are
located in the wheel. Tire -mounting tools
should not be used in the area of theva lve.
This could otherwise damage the electronic
component parts. #
Have the tires changed at a qualified
specialist workshop onl y. *
NO
TEDama getosummer tires at low
ambient temp eratures At
low ambient temp eratures, tears could
fo rm when driving with summer tires, caus‐
ing permanent damage tothe tires. #
Attemp eratures below 45 °F (7 °C),
use M+S tires . Ac
cessory pa rts th at are not appr ovedfo ryo ur
ve hicle byMercedes-Benz or are not being used
cor rectly can impair the operating saf ety.
Before pu rchasing and using non-appr oved
accesso ries, visit a qualified specialist workshop
and inquire about:
R Suitability
R Legal stipulations
R Factory recommendations &
WARNING Risk of accident wi thhigh
per form ance tires
The special tire tread in combination with the
optimized tire compound means that therisk
of skidding or hydroplaning on wetro ads is
inc reased.
In addition, the tire grip is greatly reduced at
a low outside temp erature and tire running
te mp erature. #
Switch on the ESP ®
and adapt your
driving style accordingly. #
Use M+S tire at outside temp eratures
of less than 10 °C (50 °F). Wheels and tires
397

Obser
vethefo llowing when selecting, ins talling
and replacing tires:
R Only use tires and wheels of the same type
(summer tires, winter tires, MOEx tended
tires) and the same make.
R Only 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.
R Only ins tall tires of the cor rect size onto the
wheels.
R Vehicles with a tire pressure monitoring
sy stem: All ins talled wheels must be equip‐
ped with functioning sensors forth e tire
pressure monitoring sy stem.
R Attemp 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 the004D snowflake sym‐
bol in addition tothe M+S marking pr ovide
th e best possible grip in wintry road condi‐
tions. R
For M+S tires, only use tires with the same
tread.
R Obser 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 byan appropriate
label in the driver's field of vision.
R Break in new tires at moderate speeds for
th efirs t 60 miles (100 km).
R Replace the tires af ter six years at the latest,
re ga rdless of wear.
R When 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‐
tac t a qualified specialist workshop.
Be sure toalso obse rveth efo llowing fur ther
re lated subjects:
R Notes on tire pressure (→ page377) R
Tire and Loading In form ation placard
(→ page 384)
R Tire size designation, load-beari ng capacity,
speed rating and load ind ex (→page 391)
R Tire pressure table (→ page379) Note
s onrotating wheels &
WARNING Risk of inju rythro 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. #
Rotate front and rear wheels on lyifthe
wheels and tires are of the same dimen‐
sions. 398
Wheels and tires