
and one-half times aswell onthe governmenttesttrack as a tire graded100.
Therelative performance of tires depends uponthe actual conditions oftheir use, however,andmay depart significantly fromthe norm duetovariations in driving habits, service practices anddifferences inroadcharacteristics and climateconditions.
Tractiongrade
\nDANGERRisk of accident duetoinade‐quate traction
The tractiongrade assignedtothis tire isbased onstraight-ahead braking tractiontests, and does not include either accelera‐tion, cornering,hydroplaning or peak tractioncharacteristics.
Always adaptyour drivingstyle anddrive at a speedtosuitthe prevailingtraffic andweather conditions.
NOTEDamagetothe drivetrain fromwheelspin
Avoid wheelspin.
The traction grades – from highesttolowest –are AA,A,B and C. Those gradesrepresentthetire's abilitytostop onwet pavement as meas‐ured under controlled conditions on specifiedgovernmenttestsurfaces made of asphalt andconcrete.
Temperaturegrade
\nWARNINGRisk of accident from tireoverheating and tirefailure
Thetemperature gradeforthis tire is estab‐lishedfor a tirethat is properly inflated andnotoverloaded. Excessive speed, underinfla‐tion, orexcessive loading, either separatelyor in combination, can causeexcessive heatbuild-up and possible tirefailure.
Observetherecommended tire pres‐sures andregularlycheckthe tire pres‐
sure of all tires includingthe sparewheel.
Adjustthe tire pressure as necessary.
Thetemperature grades are A (the highest), Band C. Theyrepresentthe tire'sresistancetothegeneration of heat and its abilitytodissipateheat whentested under controlled conditions ona specified indoor laboratorytestwheel. Sus‐tained hightemperature can causethe materialofthe tiretodegenerate andreduce tire life, andexcessivetemperature can leadtosudden tirefailure. Grade C correspondstoa level of per‐formance which all passenger car tires mustmeet undertherequirements ofthe US Depart‐ment ofTransportation.
DOT,TireIdentificationNumber (TIN)
US tireregulationsstipulatethateverytire man‐ufacturer orretreader mustimprint a TIN in oronthe sidewall of each tire produced.
398Wheels and tires

Preceding letter11:RWithout: passengervehicle tires accordingtoEuropean manufacturingstandards.
R"P": passengervehicle tires accordingtoUSmanufacturingstandards.
R"LT": light truck tires accordingtoUS manu‐facturingstandards.
R"T": compact emergency sparewheels withhigh tire pressurethat are only designedfortemporary use in an emergency.
Aspectratio33:Ratio between tire height and tire width in per‐cent (tireheight dividedbytire width).
Tire code44(tiretype):R"R"radial tire
R"D": bias ply tire
R"B": bias belted tires
R"ZR":radial tire with a maximum speed above149mph (240 km/h) (optional)
Rim diameter55:The diameter ofthe bead seat (notthe diameteroftherimflange). Therim diameter is specifiedin inches (in).
Load-bearing index66:Numerical codethat specifiesthe maximumload-bearing capacity of a tire (e.g. "91" corre‐spondsto1356 lbs (615kg)).
The load-bearing capacity ofthe tire must be atleast halfthe permissible axle load ofyourvehi‐cle. Do notoverloadthe tiresbyexceedingthespecified load limit.
See also:
RMaximum permissible load ontheTireandLoading Information placard (→page 393)
RMaximum tire load (→page 399)
RLoad index
Speedrating77:Specifiesthe approved maximum speed ofthetire.
An electronic speed limiter preventsyourvehicle fromexceeding a speed of130mph(210km/h).
Makesurethatyour tires havetherequiredspeedrating.You can obtain information ontherequired speedrating from an authorizedMercedes-Benz Center.
Summer tires
IndexSpeedrating
Qupto100mph (160 km/h)
Rupto106mph (170 km/h)
Supto112mph (180 km/h)
Tupto118mph (190 km/h)
Hupto130mph (210km/h)
Vupto149mph (240 km/h)
Wupto168mph (270 km/h)
Yupto186mph (300 km/h)
Wheels and tires401

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

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