wheel MERCEDES-BENZ C CLASS 2019 Manual Online

Calculationexamplefor determiningthemaximum load
Thefollowingtable showsexamples of howtocalculatetotal and load capacities withvarying
seating configurations and different numbersand sizes of occupants. Thefollowingexamplesuse a maximum load of1500 lbs (680kg).Thisisfor illustration purposes only.Make sureyou are usingthe actual load limitforyourvehi‐
clestated onyourvehicle'sTireand LoadingInformation placard (page 399).
The highertheweight of allthe occupants,thesmallerthe maximum loadfor luggage.
Step 1
Example1Example 2
Combined maximumweight of occupants andload (data fromtheTireand Loading Informationplacard)
1500 lbs (680kg)1500 lbs (680kg)
Step 2
Example1Example 2
Number of people inthevehicle (driver andoccupants)51
Distribution ofthe occupantsFront: 2
Rear: 3
Front: 1
Wheels and tires401

Tirelabeling
Overview of tire labeling
1Uniform TireQuality GradingStandard(page 403)
2DOT,TireIdentificationNumber(page 404)
3Maximum tire load (page 405)
4Maximum tire pressure (page 406)
5Manufacturer
6Characteristics ofthe tire (page 406)
7Tiresize designation, load-bearing capacity,speedrating and load index(page 406)
8Tirename
The datashown inthe image isexampledata.
TireQuality Grading
In accordance withthe US Department ofTrans‐portation's "Uniform TireQuality GradingStand‐ards", tire manufacturers arerequiredtogradetheir tires onthe basis ofthefollowingthree per‐formancefactors:
1Treadweargrade
2Tractiongrade
3Temperature grade
The data shown inthe image isexampledata.
The classification is not legallystipulatedforCanada, but it isgenerallystated.
TreadweargradeThe treadwear grade is a comparativeratingbased onthewearrateofthe tire whentestedunder controlled conditions on a specifiedtesttrack ofthe US Department ofTransportation.Forexample, a tiregraded150wouldwear one
Wheels and tires403

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.
404Wheels and tires

The data shown inthe image isexampledata.
The TIN is a unique identification numbertoidentify tires and comprisesthefollowing:
RDOT (Department ofTransportation):tiresymbol marks1indicatingthatthe tirecomplies withtherequirements ofthe USDepartment ofTransportation.
RManufacturer identification code:manu‐facturer identification code2containsdetails ofthe tire manufacturer. New tireshavea code with two symbols.Retreadedtires havea code withfour symbols.Further
information onretreaded tires(page411).
RTiresize:identifier3describesthe tiresize.
RTiretype code:tire type code4can beusedbythe manufacturer as a codetodescribe specificcharacteristics ofthe tire.
RManufacturing date:manufacturing date5provides information aboutthe age of atire. The 1st and 2nd positionsrepresentthecalendarweek andthe 3rd and 4th positionsstatetheyear of manufacture (e.g. "3208"representsthe 32ndweek of 2008).
Information onthe maximum tire load
The data shown inthe image isexampledata.
Maximum tire load1isthe maximum permissi‐bleweightfor whichthe tire is approved.
Do notoverloadthe tiresby exceedingthe speci‐fied load limit. The maximum permissible loadcan befound onthevehicle'sTireand LoadingInformation placard onthe B-pillar onthe driv‐er's side (page 399).
Wheels and tires405

Specificationsfor maximum tire pressure
The datashown inthe image isexampledata.
Neverexceed maximum tire pressure1speci‐fiedforthe tire.
Information on tirecharacteristics
The data shown inthe image isexampledata.
This information describesthe type of tire cordandthe number of layersin sidewall1andunder tire tread2.
Tiresize designation, load-bearing capacity,speedrating and load index
\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.
406Wheels and tires

1Preceding letter
2Nominal tire width in millimeters
3Aspectratio in %
4Tirecode
5Rim diameter
6Load-bearing index
7Speedrating
8Load index
The data shown inthe image isexampledata.
Information aboutreading tire data can beobtained from anyqualified specialistworkshop.
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 399)
RMaximum tire load (page 405)
RLoad index
Speedrating77:Specifiesthe approved maximum speed ofthetire.
Wheels and tires407

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)
IndexSpeedrating
Yupto186mph (300 km/h)
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
1"ZR"stated inthe tire code.2Or "M+SM"for winter tires
408Wheels and tires

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 squareinch (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 whichthevehi‐cle is designed, multipliedby150 lb (68kg).
UniformTireQuality GradingStandards:auniformstandardtogradethequality of tireswithregardtotreadquality,tire traction andtemperaturecharacteristics. Thequalitygrading
assessment is madebythe manufacturerfollow‐ing specifications fromtheU.S. government. Thequality grade 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 neverexceedthegross axleweightrating. 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. The grossvehicleweight must notexceedthe grossvehicleweightratingGVWR as specified onthevehicleidentification plate onthe B‑pillar onthe driver'sside.
GVWR (GrossVehicleWeightRating):theGVWR isthe maximum permitted grossweightofthe fully ladenvehicle (weight ofthevehicleincluding all accessories, occupants, fuel, lug‐gageandthe trailer drawbar noseweight if appli‐cable). The grossvehicleweightrating is speci‐
Wheels and tires409

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 ifthese 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 hourswithout 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 wheel
rim. 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.
41 0Wheels and tires

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.
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
Wheels and tires411