2012 MERCEDES-BENZ M-Class Owner's Manual

You
should payspec ialattent ion toroad
con dition swhen temperat uresarearound
the free zingpoint .
Merc edes- Benzrecomm endsaminimum tire
tread depth of1
/ 6in
(4 mm) forallfour winter
tires (Ypage 352)tom aint ainnorm aldriv ing
ch arac teris tic sin wint er.Win tertir es can
reduc eth ebrak ingdist anceonsnow cove red
su rfa ces incomp arison tosumme rtires.
St oppin gdist ance,howeve r,is still
con siderably greaterthan when theroad is
not covered withiceorsno w.Take
appropr iatecare when driving.
! Avoid wheelspin .This can lead todamage
to the drive train. Temp
erature G
WARNING The
temperature gradeforthis tireis
established foratire that isproperly inflated
and notoverloaded. Excessive speed,
underinflation, orexcessive loading,either
separately orincombination, cancause
excessive heatbuild-upand possible tire
failure.
The temperature gradesareA(the high est),
B, and C.Theserep resent thetire's
res istanc eto the genera tiono fheat and its
ability todissipate heatwhen testedunder
con trolled conditions onaspecified indoor
laboratory testwheel. Sustain edhigh
temper aturecancause thematerial ofthe tire
to degenerat eand reduce tirelife, and
exc essive temper aturecanlead tosudden
tire failure. Thegrade Ccorresponds toalevel
of performanc ewhich allpassenger cartires
must meet under theFederal MotorVehicle
Safety Standard No.109. Grades Band A
represent higherlevelsofperformanc eon the
laboratory testwheel thantheminimum
required bylaw. Tire
labeling Tire
labeling overview
The following markings areonthe tire in
addition tothe tire name (sales designation)
and themanufacturer 'sname: :
Uniform tireQuality Grading Standard
(Y page 371)
; DOT, TireIdent ification Number
(Y page 370)
= Maximum tireload (Ypage 365)
? Maximum tirepressure (Ypage 356)
A Manufacturer
B Tire material (Ypage 371)
C Tire size designation, load-bearing
capacity andspeed rating(Ypage 368)
D Load index (Ypage 370)
E Tire name i
Tire
data isvehicle-specif icand may
deviate fromthedata inthe example. Tir
elabeling
367Wheels and tires Z

Tire
size des ignati on,load -bea ring
cap acit yand speed ratin g :
Tire width
; Nom inalaspec tratio in%
= Tire code
? Rim diame ter
A Load bearingindex
B Spe edrating i
Tire
datais veh icle-spec ificand may
devi atefrom thedat ain theex ample .
Gener al:depen dingon theman ufacturer's
st and ards ,th esiz eimpr inted inthetir ewall
may notco ntain any letters or may contain
on elet tert hat precedes thesize description.
If there isno letter preceding thesize
description (asshown above): theseare
passenger vehicletiresaccording to
European manufacturing standards.
If "P" precedes thesize description: theseare
passenger vehicletiresaccording toU.S.
manufacturing standards.
If "LT" precedes thesize description: these
are light truck tiresaccording toU.S.
manufacturing standards.
If "T" precedes thesize description: theseare
compact emergency sparewheels athigh tire
pressure, tobe used onlytemporarily inan
emergency.
Tire width: tirewidth :shows thenominal
tire width inmillimeters.
Nominal aspectratio: aspect ratio;isthe
size ratio between thetire height andthetire
width andisshown inpercent .The aspect ratio
iscalculated bydividing thetire width by
the tire height.
Tire code: tirecode =specifies thetire type.
"R" represents radialtires."D"represents
diagonal tires,"B"represents diagonalradial
tires.
Optionally, tireswithamaximum speedof
over 149mph(240 km/h)mayhave "ZR"in
the size description dependingonthe
manufacturer (e.g.245/ 40ZR18).
Rim diamet er:rim diameter ?isthe
diameter ofthe bead seat,notthediameter
of the rim flange. Therimdiameter is
specified ininches (in).
Load bearing index:loadbearing indexA
is anumerical codewhich specifies the
maximum load-bearing capacityofatire. G
WARNING The
tireload rating mustalwaysbe atleast
half ofthe GAWR ofyour vehicle. Otherwise,
sudden tirefailure maybethe result which
could cause anaccident and/orserious injury
to you orothers.
Always replace rimsandtires withrims and
tires having thesame specifications
(designation, manufacturer andtype) as
shown onthe original part. G
WARNING Do
not overload thetires byexceeding the
specified loadlimit asindicated onthe Tire
and Loading Informationplacard onthe
driver's doorB-pillar. Overloading thetires
can overheat them,possibly causinga
blowou t.Overloading thetires canalso result
in handling orsteering problems, orbrake
failure.
Example:
The load bearing index91isequiva lenttoa
maximum loadof1356 lbs(615 kg)that the
tire can carry. Forfurther information onthe
maximum tireload inkilograms andpounds,
see (Ypage 365). 368
Tire
labeli ngWheels and tires

For
furth erinfor mationonthe loadbea ring
inde x,see Loadinde x(Ypage 370).
Speed rating: speed ratingB specifies the
approved maximum speedofthe tire. G
WARN
ING Even
when permit tedbylaw, never operate a
vehicle atspeeds greater thanthemaximum
speed ratingof the tires .
Ex ceedin gthe maximum speedforwhich tires
are rated canlead tosudden tirefailure,
causing lossofvehicle controland possibly
resultin gin an acciden tand/o rserious
personal injuryandpossible death,foryou
and forother s.
Regardless ofthe speed ratingalways
obser vethe speed limits.Dr ive care fully and
adapt yourdrivin gst yle tothe traffic
con ditio ns. Sum
mer tires Index Speed
rating Q Up
to100 mph (160km /h) R Up
to106 mph (170km /h) S Up
to112 mph (180km /h) T Up
to118 mph (190km /h) H Up
to130 mph (210km /h) V Up
to149 mph (240km /h) W Up
to168 mph (270km /h) Y Up
to186 mph (300km /h) ZR..
.Y Up
to186 mph (300km /h) ZR..
.(..Y) Abov
e186 mph (300km /h) ZR Abov
e149 mph (240km /h) R
Opt ionally, tires with amaxim umspeed of
over 149mph (240km /h) may have "ZR"
in the size desc ription depen dingonthe
manuf acturer (e.g.245 /40ZR 18). The
servicespec ification scon sist ofload
bearin gindex Aand speed rating B.
R Ifthe size desc ription ofyour tireinc ludes
"ZR" andthereare noserv ice
spec ification s,ask thetiremanuf acturer in
order tofindout themaxim umspeed.
If aserv icespec ification isavailable, the
maxim umspeed islimit edacc ordin gto the
speed rating inthe serv icespec ification .
Ex ample: 245/40ZR 18 97Y.Inthis
exam ple,"97Y"isthe serv icespec ification .
The letter"Y" repr esen tsthe speed rating
and themaxim umspeed ofthe tireis
limit edto186 mph (300km /h).
R Ev ery tirethat hasamaxim umspeed above
186 mph (300km /h) must have"ZR"inthe
size desc ription and theserv ice
spec ification mustbegiven inbrac kets.
Ex ample: 275/40ZR 18 (99 Y).The speed
rat ing "(Y)" shows thatthemaxim umspeed
of the tireis above 186mph (300km /h).
Ask thetiremanuf acturer tofindout the
maxim umspeed. All-weat
hertires and winter tires Index Speed
rating Q
M+S 29 Up
to100 mph (160km /h) T
M+S 29 Up
to118 mph (190km /h) H
M+S 29 Up
to130 mph (210km /h) V
M+S 29 Up
to149 mph (240km /h) i
Not
alltires that have theM+S
ident ification offerthe drivin g
char acterist icsofwint ertires. Wint ertires
have, inadditio ntothe M+S identificat ion,
the i snow flakesymbol onthe tire
sidewal l.Tires withthisidentificat ionfulfill
the requirements ofthe Rubber
Manufacturers Association (RMA) andthe
Rubber Association ofCanada (RAC)
regarding thetire tract iononsnow and
29 Or M+Si forwinter tires. Tir
elabeling
369Wheels and tires Z

have
been especiall ydeveloped fordriving
on snow.
An electronic speedlimiter prevents your
vehicle fromexceeding aspeed of
130 mph (210 km/h).
The speed ratingoftires mounted atthe
factory maybehigher thanthemaximum
speed thattheelectronic speedlimiter
permits.
Make surethatyour tires have therequired
speed ratingasspecified inthe "Tires"
section (Ypage 375), e.g.ifyou buy new
tires.
Further information aboutreading tiredata
can beobtained fromanyqual ified specialist
workshop, e.g.anauthorized Mercedes-Ben z
Center. Load
index i
Tire
data isvehicle-specific andmay
deviate fromthedata inthe example.
In addition tothe load bearing index,load
index :may beimprinted aftertheletters
that identify speedratingB(Ypage 368)on
the sidewa llof the tire.
R Ifno specification isgiven: notext (asinthe
example above),represents astand ard
lo ad (SL )tir e
R XL orExtra Load:rep resents arei nfor ced
tir e R
Ligh tload: represent sa light loadtire
R C, D, E:represent sa load range that
depends onthe maximum loadthatthetire
can carry atacert ainpressure DOT,
TireIdentification Number(TIN)
U.S. tireregulations prescribethatevery
manufacturer ofnew tires orretreader hasto
imprint aTIN inor on the sidewal lof each tire
produced. The
TINisaunique identificat ionnumber. The
TIN enables thetire manufacturer sto inform
purchasers ofrecalls andother safety-
relevant matters.Itmakes itpossible forthe
purchaser toeasily identify theaffect edtires.
The TINismade upofmanufacturer
identificat ioncode ;,tire size =,tire type
code ?and manufacturin gdate A. i
Tire
data isvehicle-specif icand may
deviate fromthedata inthe example.
DOT (Departm entofTransport ation):tire
symbol :indicates thatthetire complies
with therequirements ofthe U.S. Departm ent
of Transport ation.
Manufa ctureridentification code:
manufacturer identificationcode ;provides
details onthe tire manufacturer .New tires
have acode withtwosymbols. Retreaded
tires have acode withfoursymbols.
Further informationabout retreaded tires
(Y page 350).
Tire size: identifier =describes thetire size. 370
Tir
elabelingWheels and tires

Tire
type code: tiretypecod e? can be
us ed bythe manuf actu rerasacod eto
de scri bespe cificcharacteristics ofthe tire.
Date ofmanuf acture:date ofmanufacture
A provides information abouttheage ofa
tire. Thefirst andsecond positions represent
the week ofmanufacture, startingwith "01"
for the first calendar week.Positions three
and four represent theyear ofmanufacture.
For example, atire that ismarked with
"3208", wasmanufactured inweek 32in
2008. Tire
character istics i
Tire
data isvehicle-specific andmay
deviate fromthedata inthe example.
This information describesthetire cord and
the number oflay ers insidewa ll: and under
the tread ;. Defini
tionofterm sfor tires and
loading Tire
plycomposition andmaterial
used
Describes thenumber ofplies orthe number
of lay ers ofrubber-coated fabricinthe tire
tread andsidewa ll.These aremade ofsteel,
nylon, polyester andother materials. Bar
Metric unitfortire pressure. Thereare
14.5 038pounds persquare inch(psi) to
1b ar; there are100k ilopasc als(kPa) to
1 bar. DOT
(Depar tment ofTransp ortation)
DO Tmark edtires fulfill therequire mentsof
the Unit edStates Depar tment of
Tran sport ation. Nor
maloccupa ntweight
The numb erofocc upant sthe vehic leis
design edtoseat ,mult iplied by68 kilog rams
(15 0lbs). Uniform
TireQualit yGra ding
Sta ndar ds
Au nifo rmstanda rdtogra dethe quality of
tire swi th reg ards totrea dqu ality ,tire trac tion
and temp eraturecha racteri stics. Rating sar e
de term inedby tire manuf actu rersus ing U.S.
gov ernm enttesti ngpro ced ures. The rating s
ar emol dedinto theside wa llof the tire. Rec
omme ndedtire pres sure
The reco mme ndedtire pressu reappliesto
the tiresmou nted atthe factory .
The Tire and Loading Info rma tionp lacard
con tain sthe recomm endedtir epress uresfor
cold tires on afully loaded vehicleand forthe
maxim umperm issible vehiclespeed.
The tirepress uretable contain sthe
rec omm endedtir epress uresforcold tires
under various operatingcon ditio ns,i.e.
diff erin gload andspeed conditio ns. Definition
ofter ms fortires and loading
371Wheels and tires Z

Incr
ease dvehicle weight dueto
opt ional equipm ent
This isthecom binedweight ofall standar d
and optionalequipm entavailable forthe
veh icle,regar dless ofwhet heritis act ually
ins talle don theveh icle ornot. Rim
This isthepart ofthew heel onwhich thetire
is mounted. GAWR
(Gross AxleWeight Rating)
The GAWR isthe maximum permissible axle
weight. Theactual loadonanaxle must never
exceed thegross axleweight rating.The
gross axleweight ratingcanbefound onthe
vehicle identification plateonthe B-pillar on
the driver's side. Speed
rating
The speed ratingispart ofthe tire
identification. Itspecifies thespeed rangefor
which thetire isapproved. GTW
(Gross Trailer Weight)
The GTW isthe weight ofatrailer including
the weight ofthe load, luggage,accessories
etc. onthe trailer. GVW
(Gross Vehicle Weight)
The gross vehicle weightcomprises the
weight ofthe vehicle including fuel,tools, the
spare wheel, accessories installed,
occupants, luggageand thedrawba r
noseweight, ifappli cable. Thegross vehicle
weight mustnotexceed thegross vehicle
weight ratingGVWR asspecified onthe
vehicle identification plateonthe Bpillar on
the drive r'sside. GV
WR (Gross Vehicle Weight Rating)
The GVWR isthe maxim umperm issible gross
weight ofafully loaded vehicle(th eweight of
the vehic leinc luding allacc essor ies,
occ upant s,fuel, luggage andthedrawbar
nos eweight ,if applicable). Thegros svehic le
weight rating isspec ified onthe vehic le
ident ification plateonthe B-pillar onthe
drive r'sside. Max
imumload edvehicle weight
The maximum weight isthesum ofthecur b
weight oftheveh icle,th eweight ofthe
acc esso ries,th eto tal load limit andthe
weight oftheopt ionalequipm entinstalle dat
th efac tory. Kilopa
scal(kPa)
Met ricunit fortirepres sure. 6.9kP ais the
equivale ntof1psi .An other unit fortire
pres sure isbar. Thereare 100k ilopasc als
(kPa) to1b ar. Load
index
In addit iontotheload beari ngind ex,th eload
ind exmay alsobeimpr inted on thesidew all
of thetir e. This spec ifiesthe load bearing
capacity moreprecisely. Curb
weight
The weight ofavehicle withstandard
equipment includingthemaximum capacity
of fuel, oiland coolant. Italso includes theair-
condition ingsystem andoptional equipment
if these areinstalled inthe vehicle, butdoes
not include passengers orlugga ge. 372
Defin
itionofterm sfor tires andloadingWheels and tires

Maximum
loadrating
The maximu mload rating inkilograms or
pounds isthe maximum weightforwhich a
tire isapproved. Maximu
mperm issible tirepressur e
Maximum permissible tirepressure forone
tire. Maximu
mload onone tire
Maximum loadonone tire. This iscalculated
by dividing themaximum axleload ofone axle
by two. PSI
(pounds persquar einch)
As tand arduni tofm easure fortire pressure. Aspect
ratio
Relationship betweentireheight andtire
width inpercen t. Tir
epr essure
This ispressure insidethetire applying an
outward forceto each square inchofthe tire's
surface. Thetirepressure isspecified in
pounds persquare inch(psi), inkilopascal
(kPa) orinbar. Thetirepressure shouldonly
be corr ectedwhen thetires arecold. Tir
epr essure ofcold tires
The tires arecold:
R ifthe vehicle hasbeen parked without
direct sunlight onthe tires foratleast three
hours and
R ifthe vehicle hasnotbeen driven morethan
1 mile (1.6km). Tr
ead
The part ofthe tire that comes intocon tact
with theroad. Bead
The tirebead ensures thatthetire sits
securely onthe wheel. Thereareseveral steel
wires inthe bead topreven tthe tire from
comin gloose fromthewheel rim. Sidewall
The part ofthe tire between thetread andthe
bead. Weight
ofoptional extras
The combin edweight ofthose option alext ras
that weigh morethanthereplaced standard
part andmore than2.3kilograms (5lbs).
These optionalext ras, such ashigh-
perform ancebrakes, levelcontrol, aroof rack
or ahigh-perf ormancebatter y,are not
included inthe curb weight andaccesso ry
weight. TIN
(Tire Identificat ionNum ber)
This isaunique identifierwhich canbeused
by atire manufact urertoident ifytires, for
example foraproduct recall,andthus ident ify
the purchasers. TheTINismade upofthe
manufact urer'sidentitycode, tiresize, tire
type code andthemanufact uringdate. Load
bearing index
The load bearing index(alsoloadindex) isa
code thatcontains themaximum loadbearing
capacity ofatire. Definition
ofter ms fortires and loading
373Wheels and tires Z

Trac
tion
Tra ctio nis the resultof frictio nbe twe enthe
tire sand theroadsu rfa ce. TWR
(Tongue We ight Ratin g)
The TWRsp eci fiesthe maxim um permi ssible
we ight tha tthe ball coupling ofthe trailer tow
hitch cansupport. Tread
wearindicators
Narrow bars(tread wearbars) thatare
distributed overthetire tread. Ifthe tire tread
is level withthebars, thewear limitof1
/ 16 in
(1.6 mm) hasbeen reached. Occupant
distribution
The distribution ofoccupants inavehicle at
their designated seatingpositions. Total
loadlimit
Rated cargoandlugga geload plus
68 kilograms (150lbs)times thevehicle's
designated seatingcapacity. Changing
awhee l Fl
at tire
The "Brea kdown assistance" section
(Y pag e329) contains informationandnotes
on how todea lwith afla ttire. Italso provides
inst ruct ions onchan gingawheel ormoun ting
the spare wheel/ emergencyspare wheel. Inter
chang ingthewheels G
WARN
ING Rotat
efro ntand rear wheels onlyifthe tires
are ofthe same dimen sion. If
your vehic leisequipped withmixed-s ize
tir es (diff eren ttire dimen sionsfro ntvs. rear),
tir erot ation isnot possible . G
WARN
ING Have
thetightening torque chec kedafter
chan gingawheel. Thewheels couldcome
loose ifthe yare not tightenedtoator que of
110 lb-ft(150 Nm).
Only usegenuin eMerc edes- Benzwheel bolts
specified foryour vehicle's rims.
The wear pattern son the front andrear tires
differ, depending onthe operating conditions.
Rotate thewheels beforeaclear wearpattern
has formed onthe tires. Front tirestypically
wear more onthe shoulders andtherear tires
in the cent er.
If your vehicle's tireconfiguration allows,you
can rotate thewheels according tothe
intervals inthe tire manufacturer's warranty
book inyour vehicle documents. Ifthis isnot
availa ble,thetires should thenbereplaced
every 3000to6000 miles
(5000 to10,000 km),orearl ierifthe tire wea r
requ iresthis. Donot change thedirection of
whee lrotation.
Cle anthe contact surfacesofthe whee land
the brake discthoroug hlyevery timeawhee l
is interchanged .Check thetire pressures.
Inform ationonchanging awheel and
mounting thespare wheel (Ypage 333).
! Onvehicles equippedwith atire pressure
monitor, electronic componentsare
located inthe wheel.
Tire-mountin gtools should notbeused
near thevalve. Thiscould damage the
electronic components.
Always havethetires changed ataqual ified
specialist workshop, e.g.anauthorized
Mercedes-Ben zCent er. 374
Changing
awhee lWheels and tires