winter tires MERCEDES-BENZ S CLASS 2019 Owners Manual

The systemchecksthe tire pressure andthe tiretemperature ofthe tires installed onthevehiclebymeans of a tire pressuresensor.
New tire pressure sensors, e.g. in winter tires,are automaticallytaught-in duringthefirst jour‐neytheyare used.
The tire pressure appears inthe multifunctiondisplay (→page 255).
Ifthere is a substantial pressure loss or ifthetiretemperature isexcessive,you will bewarnedinthefollowingways:
Rvia display messages (→page511)
Rviathewwarning lamp inthe instrumentcluster (→page 533)
The tire pressuremonitoring system is only anaid. It isthe driver'sresponsibilitytosetthe tirepressuretotherecommended cold tire pressuresuitableforthe operating situation. Setthe tirepressurefor cold tires using a tire pressuregauge. Notethatthe correct tire pressureforthecurrent operating situation mustfirst betaught-intothe tire pressure monitoring system.
In most cases,the tire pressure monitoring sys‐tem will automatically updatethe newreferencevalues afteryou havechangedthe tire pressure.You can, however,also updatethereferenceval‐uesbyrestartingthe tire pressure monitoringsystem manually (→page441).
System limitations
The system may be impaired or may not functioninthefollowing situations:
RIfthe tire pressure is set incorrectly
RIfthere is a sudden pressure loss caused,forexample,byaforeign object penetratingthetire
RIfthere is a malfunction causedbyanotherradio signal source
Make suretoobservethefollowing furtherrela‐ted subject:
RNotes on tire pressure (→page 435)
Checkingthe tire pressure withthe tire pres‐sure monitoring system
Requirements:RThe ignition is switched on.
On-board computer:
,Service.Tires
One ofthefollowing displaysappears:
RCurrent tire pressure of eachwheel:
RTire pressure will be displayed after driving afew minutes
RTire Pressure Monitor Active:theteach-inprocess ofthe system is notyet complete.The tire pressure are already being moni‐tored.
#Comparethe tire pressure withtherecom‐mended tire pressureforthe current operat‐
440Wheels and tires

IndexSpeedrating
ZR...Y1upto186mph (300 km/h)
ZR...(..Y)1over186mph (300 km/h)
ZR1over149mph (240 km/h)
RSpecifyingthe speedrating asthe "ZR" indexin tire code4is optionalfor tires upto186mph (300 km/h).
RIfyour tire code4includes "ZR" andthereis no speedrating7,find out whatthe max‐imum speed is fromthe tire manufacturer.
RIf load-bearing index6and speedrating7are in brackets,the maximum speedrating ofyour tire is above186mph (300 km/h).Tofind outthe maximum speed, askthe tiremanufacturer.
All-weather tires and winter tires
IndexSpeedrating
Q M+S2upto100mph (160 km/h)
T M+S2upto118mph (190 km/h)
H M+S2upto130mph (210km/h)
V M+S2upto149mph (240 km/h)
Winter tires beartheMsnowflake symboland fulfilltherequirements oftheRubber Manu‐facturers Association (RMA) andtheRubberAssociation of Canada (RAC)regardingthe tiretraction on snow.
Load index88:RNo specification given:standard load (SL)tire
R"XL" or "Extra Load":extra load tire orrein‐forced tire
R"Light Load": light load tire
R"C", "D", "E": a loadrangethat depends onthe maximum loadthatthe tire can carryat acertain pressure
Definition oftermsfor tires and loading
Tirestructureandcharacteristics:describesthe number of layersorthe number ofrubber-coated belts inthe tire contact surface andthetirewall. These are made ofsteel,nylon, poly‐ester andother materials.
Bar:metric unitfor tire pressure.14.5038 pounds per square inch (psi) and100 kilopascal (kPa) isthe equivalent of one bar.
DOT (Department ofTransportation):DOT-marked tires fulfilltherequirements oftheUS Department ofTransportation.
Averageweight ofthevehicle occupants:thenumber ofvehicle occupantsfor which thevehi‐cle is designed, multipliedby150 lb (68kg).
1"ZR"stated inthe tire code.2Or "M+SM"for winter tires
Wheels and tires451

Observethefollowing when selecting, installingandreplacing tires:
ROnly use tires and wheels ofthe same type(summer tires, winter tires, MOExtendedtires) andthe same make.
ROnly install wheels ofthe same size on oneaxle (left andright).
It is only permissibletoinstall a differentwheel size intheevent of aflat tire in ordertodrivetothe specialistworkshop.
ROnly install tires ofthe correct size ontothewheels.
RVehicles with a tire pressure monitoringsystem:All installed wheels must be equip‐ped with functioning sensorsforthe tirepressure monitoring system.
RAttemperatures below 45 °F (7 °C), use win‐ter tires or all-season tires marked M+Sforall wheels.
Winter tires bearingtheMsnowflake sym‐bol in additiontothe M+S marking providethe best possible grip in wintryroad condi‐tions.
RFor M+S tires, only use tires withthe sametread.
RObservethe maximum permissible speedforthe M+S tires installed.
Ifthis is belowthevehicle's maximum speed,this must be indicatedbyan appropriatelabel inthe driver'sfield of vision.
RBreak in new tires at moderate speedsforthefirst 60 miles (100 km).
RReplacethe tires after sixyears atthe latest,regardless ofwear.
RWhenreplacing with tires that do notfea‐turerun-flatcharacteristics:vehicles withMOExtended tires are not equipped with aTIREFIT kit atthefactory.Equipthevehiclewith a TIREFIT kit afterreplacing with tiresthat do notfeaturerun-flatcharacteristics,e.g. winter tires.
For more information on wheels and tires, con‐tact aqualified specialistworkshop.
Be suretoalso observethefollowing furtherrelated subjects:
RNotes on tire pressure (→page 435)
RTireand Loading Information placard(→page442)
RTiresize designation, load-bearing capacity,speedrating and load index (→page449)
RTirepressuretable (→page 437)
Notes onrotating wheels
&WARNINGRisk of injurythrough differ‐ent wheel sizes
Interchangingthe front andrear wheels ifthewheels or tires havedifferent dimensionsmay severely impairthe drivingcharacteris‐tics.
The wheel brakes or wheel suspension com‐ponents may also be damaged.
#Rotatefront andrear wheels onlyifthewheels and tires are ofthe same dimen‐sions.
456Wheels and tires