tire pressure MERCEDES-BENZ C CLASS 2019 Owner's Manual

Screwthevalve cap ontothevalve.
Furtherrelated subjects:
RNotes on tire pressure (page 392)
RTirepressuretable (page 393)
RTireand Loading Information placard(page 399)
Tirepressure monitoring system
Function ofthe tire pressure monitoring sys‐tem
\nDANGERRisk of accident duetoincor‐rect tire pressure
Every tire, includingthe spare (if provided),should bechecked when cold at least once amonth and inflatedtothe pressurerecom‐mendedbythevehicle manufacturer (seeTireand Loading Information placard ontheB-pillar onthe driver’sside orthe tire pres‐sure label onthe inside ofthe fuelfillerflapofyourvehicle). Ifyourvehicle has tires of adifferent sizethanthe size indicated onthe
Tireand Loading Information placard orthetire pressuretable,you needtodeterminethe proper tire pressureforthose tires.
As an added safetyfeature,yourvehicle hasbeen equipped with a tire pressure monitor‐ing system (TPMS)that illuminates a low tirepressure indicator lamp when one or more ofyour tires are significantly underinflated.Accordingly, ifthe low tire pressure indicatorlamp lights up,you shouldstop andcheckyour tires as soon as possible, and inflatethemtothe proper pressure. Driving on asignificantly underinflated tire causesthe tireto overheat and can leadtotirefailure.Underinflation also increases fuel consump‐tion andreduces tire tread life, and mayaffectthevehicle's handling and braking abil‐ity. Please notethatthe TPMS is not a substi‐tutefor proper tire maintenance, and it isthedriver'sresponsibilitytomaintain correct tirepressure,even if underinflation has notreachedthe leveltotrigger illumination ofthe TPMS low tire pressure indicator lamp.
Yourvehicle has also been equipped with aTPMS malfunction indicatortoindicate whenthe system is not operating properly. TheTPMS malfunction indicator is combined withthe low tire pressure indicator lamp. Whenthe system detects a malfunction,the indica‐tor lamp willflashfor approximatelya minuteandthenremain continuously illuminated.This sequence will continue upon subsequentvehiclestart-ups as long asthe malfunctionexists.
Whenthe malfunction indicator is illumina‐ted,the system may not be abletodetect orsignal low tire pressure as intended. TPMSmalfunctions may occurfor avariety ofrea‐sons, includingthe installation of incompati‐blereplacement or alternate tires or wheelsonthevehiclethat preventthe TPMS fromfunctioning properly.
Alwayscheckthe TPMS malfunctionwarninglamp afterreplacing one or more tires orwheels onyourvehicletoensurethatthereplacement or alternate tires and wheels
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allowthe TPMStocontinuetofunction prop‐erly.
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 andthe tiretemperatureappear inthe multifunction display(page 396).
Ifthere is a substantial pressure loss or ifthetiretemperature isexcessive,you will bewarnedinthefollowingways:
Rvia display messages (page 466)
Rviathewwarning lamp inthe instrumentcluster (page 490)
The tire pressuremonitoring system is only anaid. It isthe driver'sresponsibilitytosetthe tirepressuretotherecommended cold tire pressuresuitableforthe operating situation. Setthe tirepressurefor cold tires using a tire pressure
gauge.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 (page 397).
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 392)
Checkingthe tire pressure withthe tire pres‐sure monitoring system
Requirements:RThe ignition is switched on.
On-board computer:
ServiceTires
One ofthefollowing displaysappears:
RCurrent tire pressure and tiretemperature ofthe individual wheels:
RTire pressure will be displayed after driving afew minutes
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RTire Pressure Monitor Active:theteach-inprocess ofthe system is notyet complete.The tire pressures are already being moni‐tored.
Comparethe tire pressure withtherecom‐mended tire pressureforthe current operat‐ing condition (page393). Observethenotes on tiretemperature (page 392).
Thevalues displayed inthe multifunction dis‐play may deviate fromthose ofthe tire pres‐suregauge astheyrefertosea level.Athighaltitudes,the tire pressurevalue indicatedbya pressuregauge are higherthanthoseshownbythe on-board computer. Inthiscase, do notreducethe tire pressure.
Make suretoobservethefollowing furtherrela‐ted subject:
RNotes on tire pressure (page 392)
Restartingthe tire pressure monitoring sys‐tem
Requirements:RTherecommended tire pressure is correctlysetfortherespective operatingstatus oneach ofthefour wheels (page 392).
Restartthe tire pressure monitoring system inthefollowing situations:
RThe tire pressure haschanged.
RThe wheels or tires havebeenchanged ornewly installed.
On-board computer:
ServiceTires
Swipe downwards onTouch Control ontheleft-hand side ofthesteering wheel.TheUse Current Pressures as New Refer-ence Values?message is shown inthe multi‐function display.
Tobeginrestart, pressTouch Control ontheleft-hand side ofthesteering wheel.TheTire Press. Monitor Restartedmessage isshown inthe multifunction display.
Currentwarning messages are deleted andtheyellowwwarning lamp goes out.
Afteryou havebeen drivingfor afewminutes,the systemcheckswhetherthe cur‐rent tire pressures are withinthe specifiedrange. The current tire pressures arethenaccepted asreferencevalues and monitored.
Make suretoobservethefollowing furtherrela‐ted subject:
RNotes on tire pressure (page 392)
Radio equipment approval ofthe tire pres‐sure monitoring system
Radio equipment approval numbers
CountryRadio type approval number
Canada IC: 2546A-GG4T
IC: 2546A-DG6W2D4
IC: 2546A-MC34MA4
USAFCC ID: MRXGG4T
FCC ID: MRXDG6W2D4
FCC ID: MRXMC34MA4
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Further information onthe declaration of con‐formityfor wirelessvehicle components(page 25).
Tirepressure losswarning system
Function ofthe tire pressure losswarningsystemThe tire pressure losswarning systemwarnsthedriverbymeans of display messages whenthereis a severetire pressureloss.
After achange in tire pressure, a wheelrotationor a tirechange, or ifyou havere-installedwheels or tires,the tire pressure losswarningsystem hastoberestarted (page 398).
The tire pressure losswarning system does notreplacethe needtoregularlycheckthe tire pres‐sure.
System limitations
The system may be impaired or may not functionparticularlyinthefollowing situations:
RIncorrectly set tire pressure
RSudden pressure loss caused,forexample,byaforeign object penetratingthe tire
RSteady pressure loss in several tires
The system has arestricted or delayed functionparticularly inthefollowing situations:
RPoor ground conditions, e.g. snow or gravel
RDriving withsnowchains
RWhen adopting averysporty drivingstylewith high cornering speeds or sudden accel‐eration
RDriving with a high load
Be suretoalso observethefollowing furtherrelated subjects:
RNotes on tire pressure (page 392)
RDisplay messages aboutthe tires(page 466)
Restartingthe tire pressure losswarningsystem
Requirements:RTherecommended tire pressure is correctlysetfortherespective operatingstatus oneach ofthefour wheels (page 392).
Restartthe tire pressure losswarning system inthefollowing situations:
RThe tire pressure haschanged.
RThe wheels or tires havebeenchanged ornewly installed.
On-board computer:
ServiceTires
Swipe downwards ontheTouch Control onthe left-hand side ofthesteering wheel.TheTire Pressure Control SystemActiveRestart: Press Touch Controlmessageis shown inthe multifunction display.
Restartthe tire pressure losswarning system inthefollowing situations:
RThe tire pressure haschanged.
RThe wheels or tires havebeenchanged ornewly installed.
Tobegintherestart, presstheTouch Controlonthe left-hand side ofthesteering wheel.TheTire Pressure Now OK?message isshown inthe multifunction display.
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SelectYes.
Toconfirmtherestart, presstheTouch Con‐trol onthe left-hand side ofthesteeringwheel.TheRun Flat Indicator Restartedmessage isshown inthe multifunction display.
Afteryou havedrivenfor afew minutes,thetire pressurelosswarning system monitorsthe set tire pressures of allthe tires.
Be suretoalso observethefollowing furtherrelated subjects:
RNotes on tire pressure (page 392)
Loadingthevehicle
Notes onTireand Loading Information plac‐ard
\nWARNINGRisk of accident fromoverloa‐ded tires
Overloaded tires mayoverheat and burstas aconsequence. Overloaded tires can alsoimpairthesteering and handlingcharacteris‐tics and leadtobrakefailure.
Observethe load-bearing capacity ofthe tires.
The load-bearing capacity must be atleast halfthe gross axleweightrating ofthevehicle.
Neveroverloadthe tiresby exceedingthe maximum load.
TheTireand Loading Information placard is onthe B-pillar onthe driver's side ofthevehicle.
1Tireand Loading Information placard
The data shown inthe illustration isexampledata.
TheTireand Loading Information placard shows:
RMaximum number of seats2accordingtothe maximum number of people permittedtotravel inthevehicle.
RMaximum permissible load3comprisesthegrossweight of allvehicle occupants, loadand luggage.
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RRecommended tire pressures1for coldtires. Therecommended tire pressures arevalidforthe maximum permissible load anduptothe maximum permissiblevehiclespeed.
Please also note:
RInformation on permissibleweights and loadsonthevehicle identification plate(page 423).
RInformation on tire pressure inthe tire pres‐suretable (page 393).
Furtherrelated subjects:
RDeterminingthe maximum permissible load(page 400)
RNotes on tire pressure (page 392).
Determiningthe maximum permissible load
Thefollowingsteps havebeen developed asrequired of all manufacturers underTitle 49,Code ofU.S.FederalRegulations,Part575, pur‐suanttothe "NationalTraffic and MotorVehicleSafetyAct of1966".
Step 1:locatethestatement "The combinedweight of occupants and load should neverexceed XXXkgor XXX lbs." ("The combinedweight of occupants and load should neverexceed XXXkgor XXX lbs.") onyourvehicle'sTireand Loading Information placard.
Step 2:determinethe combinedweight ofthe driver and passengersthat will be travel‐ing inyourvehicle.
Step 3:subtractthe combinedweight ofthedriver and passengers from XXXkgorXXX lbs.
Step 4:theresultingfigure equalsthe per‐missible cargo and luggage load capacity.Forexample: If "XXX" equals1400 lbs andtherearefiveoccupants inyourvehicle with aweight of150 lbs each,the maximum cargoand luggage load capacity is 650 lbs (1400 -750 (5 x150) = 650 lbs).
Step 5:determinethe combinedweight ofluggage and loadthatthevehicle will be car‐rying.For safetyreasons,thisweight may notsafelyexceedtheavailable cargo and lug‐gageload capacity calculated instep 4.
Even ifyou havecalculatedthetotal load care‐fully,you shouldstill make surethatthe maxi‐mum permissible gross mass andthe maximumpermissible axle load ofyourvehicle are notexceeded. Details can befound onthevehicleidentification plate.
Haveyour loadedvehicle – including driver,occupants and load –weighed on avehicleweighbridge.The measuredvalues may notexceedthemaximum permissiblevaluesstated onthevehicle identification plate.
Furtherrelated subjects:
RCalculationexamplefor determiningthe max‐imum load (page 401)
RTireand Loading Information placard(page 399)
RTirepressuretable (page 393)
RVehicle identification plate
400Wheels and tires

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

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