RThe tires maywearexcessively and/orunevenly,which maygreatlyimpair tiretraction.
RThe drivingcharacteristics, aswell assteering and braking, may be greatlyimpaired.
#Comply withtherecommended tirepressure andcheckthe tire pressure ofall tires includingthe spare wheelregu‐larly:
Rat least once a month
Rwhenthe loadchanges
Rbefore embarking on a longer journey
Rif operating conditionschange, e.g. off-road driving
#Adjustthe tire pressure as necessary.
Driving withtire pressurethat istoo high ortoolow can:
RShortenthe service life ofthe tires.
RCause increased tire damage.
RAdversely affect drivingcharacteristics andthus driving safety,e.g. dueto hydroplaning.
&WARNINGRisk of an accident duetoinsufficient tire pressure
Tires with pressurethat istoo low canover‐heat and burstas aresult.
In addition,theyalso suffer fromexcessiveand/or irregularwear, which can significantlyimpairthe braking properties andthe han‐dlingcharacteristics.
#Avoidexcessively low tire pressures inallthe tires, includingthe spare wheel.
Tirepressure which istoo low can cause:
RTiredefects as aresult ofoverheating
RImpaired handlingcharacteristics
RIrregularwear
RIncreased fuel consumption
&WARNINGRisk of accident fromexces‐sive tire pressure
Tires withexcessively high pressure canburst becausetheyare damaged more easilybyhighwayfill, pot holesetc.
In addition,theyalso suffer from irregularwear, which can significantly impairthe brak‐ing properties andthe handlingcharacteris‐tics.
#Avoidexcessively high tire pressures inallthe tires, includingthe spare wheel.
Excessively high tire pressure canresult in:
RIncreased braking distance
RImpaired handlingcharacteristics
RIrregularwear
RImpaired driving comfort
RSusceptibilitytodamage
436Wheels and tires
The tire pressuretable shows therecommendedtire pressurefor all tires approvedforthisvehi‐cle. Therecommended tire pressures applyforcold tires undervarious operating conditions, i.e.loading and/or speed ofthevehicle.
If one or more tire sizes precede a tire pressure,the tire pressure informationfollowing is onlyvalidforthose tire sizes.
The load conditions "partially laden" and "fullyladen" are defined inthetablefor different num‐bersof passengers and amounts of luggage. Theactual number of seats may differ fromthis.
Some tire pressuretables only showtherimdiameter instead ofthe completetire size, e.g.R18. Therim diameter is part ofthe tire size andcan befound onthe tire sidewall (→page449).
Be suretoalso observethefollowing furtherrelated subjects:
RNotes on tire pressure (→page 435)
RTireand Loading Information placard(→page442)
RMaximum tire pressure (→page448)
Checkingtire pressures manually
#Readthe tire pressureforthe current operat‐ing conditions fromtheTireand LoadingInformation placard orthe tire pressuretable. Observethe notes on tire pressure.
#Removethevalve cap ofthe tiretobechecked.
#Pressthe tire pressuregauge securely ontothevalve.
#Readthe tire pressure.
#Ifthe tire pressure is lowerthantherecom‐mendedvalue, increasethe tire pressuretotherecommendedvalue.
#Ifthe tire pressure is higherthantherecom‐mendedvalue,release air.Todo so, pressdownthe metal pin inthevalve, e.g. usingthe tip of a penforexample. Thencheckthetire pressureagain usingthe tire pressuregauge.
#Screwthevalve cap ontothevalve.
438Wheels 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
452Wheels and tires