
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 bearthe Msnowflake 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+S M"for winter tires
402Wheels and tires

UniformTireQuality GradingStandards:auniformstandardtogradethequality of tireswithregardtotreadquality,tire traction andtemperaturecharacteristics. Thequality gradingassessment is madebythe manufacturerfollow‐ing specifications fromtheU.S. government. Thequalitygrade of a tire is imprinted onthe sidewall ofthe tire.
Recommended tire pressure:therecommen‐ded tire pressure isthe tire pressure specifiedforthe tires mountedtothevehicle atthefac‐tory.
The tire and informationtable containstherec‐ommended tire pressuresfor cold tires,the max‐imum permissible load andthe maximum per‐missiblevehicle speed.
The tire pressuretable containstherecommen‐ded tire pressuresfor cold tires undervariousoperating conditions, i.e. loading and/or speedofthevehicle.
Increasedvehicleweight duetooptionalequipment:the combinedweight of allstandardand optional equipmentavailableforthevehicle,
regardless of whether it is actually installed onthevehicle or not.
Rim:the part ofthe wheel on whichthe tire isinstalled.
GAWR (Gross AxleWeightRating):the GAWRisthe maximum permissible axle load. Theactual load on an axle must neverexceedthegrossaxleweightrating. The gross axleweightrating can befound onthevehicle identificationplate onthe B‑pillar onthe driver's side.
Speedrating:the speedrating is partofthe tireidentification. It specifiesthe speedrangeforwhich a tire is approved.
GVW (GrossVehicleWeight):the grossvehicleweight comprisestheweight ofthevehicleincluding fuel,tools,the spare wheel, accesso‐ries installed, occupants, luggage andthe trailerdrawbar noseweight, if applicable. Thegrossvehicleweight must notexceedthe grossvehicleweightratingGVWR as specified onthevehicleidentification plate onthe B‑pillar onthe driver'sside.
GVWR (GrossVehicleWeightRating):theGVWR isthe maximum permitted grossweight
ofthe fully ladenvehicle (weight ofthevehicleincluding all accessories, occupants, fuel, lug‐gageandthe trailer drawbar noseweight if appli‐cable). Thegrossvehicleweightrating is speci‐fied onthevehicle identification plate ontheB‑pillar onthe driver's side.
Maximumweight ofthe ladenvehicle:themaximumweight isthe sum ofthe curbweightofthevehicle,theweight ofthe accessories,themaximum load andtheweight of optional equip‐ment installed atthefactory.
Kilopascal (kPa):metric unitfor tire pressure.6.9 kPa correspondsto1 psi. Another unitfortire pressureis bar.100 kilopascal (kPa) equals1 bar.
Load index:in additiontothe load-bearingindex,the load index may also be imprinted onthe sidewall ofthe tire. This specifiesthe load-bearing capacity ofthe tire more precisely.
Curbweight:theweight of avehicle withstand‐ard equipment includingthe maximum capacityof fuel, oil and coolant. It also includesthe airconditioning system and optional equipment if
Wheels and tires403

these are installed onthevehicle, but does notinclude passengers or luggage.
Maximum tire load:the maximum tire load isthe maximum permissibleweight in kilograms orlbsfor whicha tire is approved.
Maximum permissible tire pressure:maxi‐mum permissible tire pressurefor one tire.
Maximum load on one tire:maximum load onone tire. This is calculatedbydividingthe maxi‐mum axle load of one axlebytwo.
PSI (pounds per square inch):standard unit ofmeasurementfor tire pressure.
Aspectratio:ratio between tire height and tirewidth in percent.
Tirepressure:pressure insidethe tire applyingan outwardforcetoeverysquare inch ofthe tire.The tire pressure is specified in pounds persquare inch (psi), in kilopascals (kPa) or in bar.The tire pressure should only be corrected whenthe tires are cold.
Cold tire pressure:the tires are cold whenthevehicle has been parkedfor at least3 hours
without direct sunlight onthe tires orthevehiclehas been drivenfor lessthan 1 mile (1.6 km).
Tirecontact surface:the part ofthe tirethatcomes into contact with theroad.
Tirebead:the purpose ofthe tire bead istoensurethatthe tire sits securely onthe wheelrim. There are several wire cores inthe tire beadtopreventthe tire fromchanging length onthewheelrim.
Sidewall:the part ofthe tire betweenthe treadandthe tire bead.
Weight of optional equipment:the combinedweight ofthe optional equipmentweighing morethanthereplacedstandard parts and morethan5 lbs (2.3kg).This optional equipment, such ashigh-performance brakes, level control system, aroof luggagerackor high-performance batteries,is not included inthe curbweight andtheweightofthe accessories.
TIN (Tire IdentificationNumber):a uniqueidentification number which can be usedby atire manufacturertoidentify tires,forexample,in a productrecall, andthus identifythe pur‐chasers. The TIN is made up ofthe manufactur‐
er's identity code, tire size, tire type code andthe manufacturing date.
Load-bearing index:the load-bearing index is acodethat containsthe maximum load-bearingcapacity of a tire.
Traction:traction isthe gripresulting from fric‐tion betweenthe tires andtheroad surface.
Wear indicator:narrowbars (treadwear bars)that are distributedoverthe tire contact surface.Ifthe tire tread is level withthe bars,thewearlimit of 1/16in (1.6 mm) has beenreached.
Distribution ofvehicle occupants:distributionofvehicle occupantsover designated seat posi‐tions in avehicle.
Maximum permissible payloadweight:nomi‐nal load and luggage load plus150 lb (68kg)multipliedbythe number of seats inthevehicle.
404Wheels and tires

Changing a wheel
Notes on selecting, installing andreplacingtires
Mercedes-AMGvehicles:observethe notes inthe Supplement. Otherwise,you may notrecog‐nize dangers.
You can askfor informationregarding permittedwheel/tire combinations at an authorizedMercedes-Benz Center.
\nWARNINGRisk of accident duetoincor‐rect dimensions of wheels and tires
If wheels and tires ofthe wrong size areinstalled,the wheel brakes or wheel suspen‐sion components may be damaged.
Alwaysreplace wheels and tires withthosethat fulfillthe specifications ofthe original part.
Whenreplacing wheels, make suretofitthecorrect:
RDesignation
RModel
Whenreplacing tires, make suretoinstallthecorrect:
RDesignation
RManufacturer
RModel
\nWARNINGRisk of injurythroughexceed‐ingthe specified tire loadrating orthepermissible speedrating
Exceedingthe specified tire loadrating orthe permissible speedrating may leadtotiredamageandtothe tires bursting.
Therefore, only use tire types and sizesapprovedforyourvehicle model.
Observethe tire loadrating and speedratingrequiredforyourvehicle.
NOTEVehicle and tire damagethroughtire types and sizesthat havenot beenapproved
For safetyreasons, onlyuse tires, wheelsand accessories which havebeen speciallyapprovedbyMercedes-Benzforyourvehicle.
These tires are specially adaptedtothe con‐
trol systems, such as ABS, ESP®and4MATIC, and marked asfollows:
RMO = Mercedes-Benz Original
RMOE = Mercedes-Benz Original Extended(run-flat tire onlyfor certain wheels)
RMO1 = Mercedes-Benz Original (only cer‐tain AMG tires)
Certaincharacteristics, such as handling,vehicle noise emissions, fuel consumption,etc. mayotherwise be adversely affected.Furthermore,other tire sizes couldresult inthe tiresrubbing againstthe body and axlecomponents when loaded. This couldresultin damagetothe tire orthevehicle.
Wheels and tires405