2018 MERCEDES-BENZ S-CLASS CABRIOLET Owner's Manual

Further related subjects:
RNo tes on tire pressure (→page 364)
RTire pressure table (→page 365)
RTire and Loading Info rmation placard
(→page 370)
Tire pressure moni toring sy stem
Fu nction of the tire pressure moni toring sys‐
te m
&
DANG ER Risk of accident due toincor‐
re ct tire pressure
Every tire, including the spare (if pr ovided),
should be checked when cold at least once a
month and inflated tothe pressure recom‐
mended bytheve hicle manufacturer (see
Ti re and Loading Info rmation placard on the
B-pillar on the driver ’sside or the tire pres‐
sure label on the inside of the fuel filler flap
of your vehicle). If your vehicle has tires of a
dif fere nt size than the size indicated on the
Ti re and Loading Info rmation placard or the
tire pressure table, you need todeterm ine
th e proper tire pressure forth ose tires.
As an added saf etyfe ature, your vehicle has
been equipped with a tire pressure monitor‐
ing sy stem (TPMS) that illuminates a low tire
pressure indicator lamp when one or more of
yo ur tires are signif icantly underinflated.
Ac cording ly, if the low tire pressure indicator
lamp lights up, you should stop and check
yo ur tires as soon as possible, and inflate
th em tothe proper pressure. Driving on a
significant lyunderinflated tire causes the tire
to ov erheat and can lead totire failure.
Un derinflation also increases fuel consump‐
tion and reduces tire tread life, and may
af fect theve hicle's handling and braking abil‐
ity. Please no tethat the TPMS is not a substi‐
tute for proper tire maintenance, and it is the
driver's responsibility tomaintain cor rect tire
pressure, even if underinflation has not
re ached the le velto trig ger illumination of
th e TPMS low tire pressure indicator lamp.
Yo ur vehicle has also been equipped with a
TPMS malfunction indicator toindicate whenthe sy stem is not operating proper ly. The
TPMS malfunction indica tor is combined with
th e low tire pressure indicator lamp. When
th e sy stem de tects a malfunction, the indica‐
to r lamp will flash for app roxima tely a minute
and then remain continuously illumina ted.
This sequence will continue upon subsequent
ve hicle start-ups as long as the malfunction
ex ists.
When the malfunction indicator is illumina‐
te d, the sy stem may not be able todetect or
signal low tire pressure as intended. TPMS
malfunctions may occur for a variet yof rea‐
sons, including the ins tallation of incompati‐
ble replacement or alternate tires or wheels
on theve hicle that pr eventthe TPMS from
functioning properly.
Alw aysch eck the TPMS malfunction warning
lamp af terre placing one or more tires or
wheels on your vehicle toensure that the
re placement or alternate tires and wheels
allow the TPMS tocontinue tofunction prop‐
erly.
Wheels and tires 367

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

Make suretoobser vethefo llowing fur ther rela‐
te d subjec t:
RNotes on tire pressure (→page 364)
Rest arting the tire pressure moni toring sys‐
te m
Requ irements
RTherecommended tire pressure is cor rectly
set forth ere spective operating condition on
each of thefo ur wheels (
→page 364).
Re start the tire pressure monitoring sy stem in
th efo llowing situations:
RThe tire pressure has changed.
RThe wheels or tires ha vebeen changed or
newly fitted.
On-boa rdcompute r:
,Service.Tires
#Swipe down wards on theTo uch Control on
th e left-hand side of thesteering wheel.
The Use Current Pressures as New Refer-
ence Values message is shown in the multi‐
function displa y.
#Pressatoconfirm there start.
The Run Flat Indicator Restarted message is
shown in the multifunction displa y.
Cur rent wa rning messages are dele ted and
th eh yellow warning lamp goes out.
Af teryo u ha vedriven for a few minutes, the
sy stem checks whe ther the cur rent tire pres‐
sure s are within the specified range. The cur‐
re nt tire pressures are then accep ted as ref‐
erence values and monitored.
Make sure toobser vethefo llowing fur ther rela‐
te d subjec t:
RNotes on tire pressure (→page 364) Ra
dio equipment appr oval of the tire pres‐
sure moni toring sy stem
Ra dio equipment appr oval numbers
Countr yRadio type appr oval number
Canada IC: 2546A-GG4; IC: 2546A- MC34MA4;
Le présent appareil est conforme
aux CNR d'Indust rie Canada
applicables aux appareils radio
exe mpts de licence. L'exploi ta‐
tion est au torisée aux deux con‐
ditions suivantes:
(1) l'appare il ne doit pas produire
de brouillage, et
(2) l'utilisateur de l'appareil doit
accep terto ut brouillage
ra dioélectri que subi, même si le
brouillage est susceptible d'en
compromett relefonctionnement.
Wheels and tires 369

CountryRadio type appr oval number
US AF CC ID: MRXGG4
FCC ID: MRXMC34MA4
This device co mplies with Part15
of the FCC Rules. Operation is
subject tothefo llowing two con‐
ditions:
(1) This device may not cause
harmful inter fere nce, and
(2) This device must accept any
inter fere nce receive d, including
inter fere nce that may cause
undesired operation.Loading theve hicle
Tire and Loading Information placard
&
WARNING Risk of accident from overloa‐
ded tires
Overloaded tires may overheat and bur stas a
consequence. Overloaded tires can also
impair thesteering and handling characteris‐
tics and lead tobrake failure.
#Obser vethe load rating of the tires.
#The load rating must be at least half the
permissible axle load of theve hicle.
#Ne verove rload the tires by exceeding
th e maximum load.
The Tire and Loading Info rmation placard is on
th e B-pillar on the driver's side of theve hicle.
1Tire and Loading Info rmation placard
370
Wheels and tires

%The data shown in the image is example
data.
The Tire and Loading Info rmation placard sho ws:
RMaximum number of seats 2according to
th e maximum number of people permitted to
tr ave l in theve hicle.
RMaximum permissible load 3comprises the
gros swe ight of all vehicle occupants, load
and luggage.
RRe commended tire pressures 1for cold
tires. The recommended tire pressures are
va lid forth e maximum permissible load and
up tothe maximum permissible vehicle
speed.
Please also no te:
RInformation on permissible weights and loads
on theve hicle identification plate
(
→page 394).
RInformation on tire pressure on the tire pres‐
sure table (→page 365).
Fu rther related subjects:
RDe term ining the maximum permissible load
(→page 371)
RNo tes on tire pressure (→page 364)
De term ining the maximum permissible load
The following steps ha vebeen de veloped as
re qu ired of all manufacturers under Title 49,
Code of U.S. Federal Regulations, Part57 5, pur‐
suant tothe "National Traf fic and Mo torVe hicle
Saf etyAc t of 1966".
#Ste p 1: locatethest atement "The combined
we ight of occupants and cargo should ne ver
exc eed XXX kgor XXX lbs." ("The combined
we ight of occupants and cargo should ne ver
exc eed XXX kgor XXX lbs.") on your vehicle's
Ti re and Loading Info rmation placard.
#Ste p 2: determ ine the combined weight of
th e driver and passengers that will be tra vel‐
ing in your vehicle.
#Ste p 3: subtract the combined weight of the
driver and passengers from XXX kgor
XXX lbs.
#Ste p 4: there sulting figure equals the per‐
missible cargo and luggage load capacity. For
ex ample: If "XXX" equals 1400 lbs and there
are five occupants in your vehicle with a
we ight of 150 lbs each, the maximum cargo
and luggage load capacity is 650 lbs (1400 -
75 0 (5 x 150) = 650 lbs).
#Ste p 5: determ ine the combined weight of
luggage and cargo that theve hicle will be
car rying. For saf etyre asons, this we ight may
not safely exceed theav ailable cargo and lug‐
ga ge load capacity calculated in step 4.
Wheels and tires 37
1

Even ifyou ha vecalculated thetot al load care‐
full y,yo u should still make sure that the maxi‐
mum permissible gross mass and the maximum
permissible axle load of your vehicle are not
exc eeded. De tails can be found on theve hicle
identification plate.
#Ha ve your loaded vehicle – including driver,
occupants and load – weighed on a vehicle
we ighbridge.
The measured values may not exceed the
maximum permissible values stated on the
ve hicle identification plate. Fu
rther related subjects:
RCalculation example for de term ining the max‐
imum load (→page 372)
RTire and Loading Info rmation placard
(→page 370)
RTire pressure table (→page 365)
RVe hicle identification plate
Calculation example for de term ining the
ma ximum load
The following table sho wsexamples of how to
calculate total and load capacities with varying seating con
figurations and dif fere nt numbe rs
and sizes of occupants. The following examples
use a maximum load of 1500 lbs (680 kg).This
is for illustration purposes on ly.Make sure
yo u are using the actual load limit foryo ur vehi‐
cle stated on your vehicle's Tire and Loading
Info rmation placard (
→page 370).
The higher thewe ight of all the occupants, the
smaller the maximum load for lug gage .
St ep 1
Example 1E xamp le 2
Combined maximum weight of occupants and
load (data from theTire and Loading Info rmation
placard) 15
00 lbs (680 kg)1 500 lbs (680kg)
37 2
Wheels and tires

Step 2
Example 1E xamp le 2
Numb er of people in theve hicle (driver and
occupants) 51
Distribution of the occupant sF ront: 2
Re ar: 3 Fr
ont: 1
We ight of occupant sO ccupant 1:150 lbs (68 kg)
Occupant 2: 180 lbs (82 kg)
Occupant 3: 160 lbs (73 kg)
Occupant 4: 140 lbs (63 kg)
Occupant 5: 120 lbs (54 kg) Occupant 1: 200 lbs (91
kg)
To talwe ight of all occupant s7 50 lbs (340kg)2 00 lbs (91kg)
Ste p 3
Example 1E xamp le 2
Pe rm issible load (maximum grossve hicle weight
ra ting from theTire and Loading Info rmation
placard minus the gross weight of all occupants) 15
00 lbs (680 kg)Ò 75 0 lbs (340 kg) = 750 lbs
(340 kg) 15
00 lbs (680 kg)Ò 200 lbs (91 kg) = 1300 lbs
(589 kg)
Wheels and tires 37
3

Tire labeling
Overview of tire labeling
1Uni form Ti reQuality Grading Standard
(→page 374)
2DO T,Tire Identification Number
(→page 375)
3Maximum tire load (→page 376)
4Ma ximum tire pressure (→page 376)
5Manu facturer
6Characteristics of the tire (→page 377)
7Tire size designation, load-beari ng capacity,
speed rating and load ind ex(→page 377)
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
374
Wheels and tires