2003 MERCEDES-BENZ C320 COUPE wheel torque

235 Operation
Tires and wheels
Tire pressure changes by approximately
1.5 psi (0.1 bar) per 18°F (10°C) of air
temperature change. Keep this in mind
when checking tire pressure where the
temperature is different from the outside
temperature.
Tire temperature and tire pressure are also
increased while driving, depending on the
driving speed and the tire load.Check the spare tire periodically for condi-
tion and inflation. Spare tires will age and
become worn over time even if never used,
and thus should be inspected and replaced
when necessary.
Rotating wheels
On vehicles with the same wheel size all
around, wheels can be rotated every 3000
to 6000 miles (5 000 to 10 000 km), or sooner if necessary, according to the de-
gree of tire wear. The same direction of tire
rotation must be retained.
Rotate the wheels before the characteris-
tic tire wear pattern becomes visible
(shoulder wear on front wheels and tread
center wear on rear wheels).
Thoroughly clean the inner side of the
wheels after each rotation. Check and en-
sure proper tire inflation pressure.
Warning!
G
Follow recommended inflation pressures.
Do not overinflate tires. Overinflating tires
can result in sudden deflation (blowout) be-
cause they are more likely to become punc-
tured or damaged by road debris, potholes
etc.
Do not underinflate tires. Underinflated tires
wear unevenly, adversely affect handling
and fuel economy, and are more likely to fail
from being overheated.
Do not overload the tires by exceeding the
specified vehicle capacity weight (as indicat-
ed by the label on the pillar in the driver’s
door opening). Overloading the tires can
overheat them, possibly causing a blowout.Warning!
G
Rotate front and rear wheels only if they are
of the same size.
Warning!
G
Have the tightening torque checked after
changing a wheel. Wheels could become
loose if not tightened with a torque of
80 ft.lb. (110 Nm).
Use only genuine Mercedes-Benz wheel
bolts specified for your vehicle's rims.

291 Practical hints
Flat tire

Unscrew the alignment bolt, install last
wheel bolt and tighten slightly.Lowering the vehicle

Lower vehicle by turning crank coun-
terclockwise until vehicle is resting ful-
ly on its own weight.

Remove the jack.
1-5 Wheel bolts

Tighten the five wheel bolts evenly, fol-
lowing the diagonal sequence illustrat-
ed (1 to 5), until all bolts are tight.
Observe a tightening torque of 80 ft lb
(110 Nm).
!To avoid paint damage, place wheel flat
against hub and hold it there while in-
stalling first wheel bolt.Warning!
G
Always replace wheel bolts that are dam-
aged or rusted.
Never apply oil or grease to wheel bolts.
Damaged wheel hub threads should be re-
paired immediately. Do not continue to drive
under these circumstances! Contact an au-
thorized Mercedes-Benz Center or call
Roadside Assistance.
Incorrect mounting bolts or improperly
tightened mounting bolts can cause the
wheel to come off. This could cause an acci-
dent. Be sure to use the correct mounting
bolts.
Warning!
G
Use only genuine equipment
Mercedes-Benz wheel bolts. They are identi-
fied by the Mercedes star. Other wheel bolts
may come loose.
Do not tighten the wheel bolts when the ve-
hicle is raised. Otherwise the vehicle could
tip over.


292 Practical hintsFlat tire
Before storing the jack in the trunk, it
should be fully collapsed, with handle
folded in.Inflating the spare tire

Take the electric air pump out of the
trunk.
1Flap
2Air hose with pressure gauge and vent
screw
3Union nut
4Electrical plug
Please exercise appropriate caution

Open flap 1 on air pump.

Pull out electrical plug4 and air hose
with the pressure gauge2.
Observe instructions on air pump label.

Remove the valve cap from valve.

Screw the air hose2 on to the tire
valve.

Insert electrical plug 4 into vehicle cig-
arette lighter socket.

To switch on the air pump turn the key
in the starter switch to position1
(page 31).

Operate air pump until the pressure
gauge displays 36 psi (2.5 bar)
This takes about five minutes for the
space tire. The air hose 2 and the union
nut 3 can become hot during inflation.
Warning!
G
Have the tightening torque checked after
changing a wheel. The wheels could come
loose if they are not tightened to a torque of
80 ft lb (110 Nm).
Warning!
G
Observe instructions on air pump label.


331 Technical terms
SRS
(S
upplemental R
estraint S
ystem)
Seat belts, emergency tensioning de-
vice and airbags. Though independent
systems, they are closely interfaced to
provide effective occupant protection.
Tele Aid* System
(T
elematic A
larm I
dentification on D
e-
mand)
The Tele Aid system consists of three
types of response: automatic and man-
ual emergency, roadside assistance
and information. Tele Aid is initially ac-
tivated by completing a subscriber
agreement and placing an acquain-
tance call.
The Tele Aid system is operational pro-
viding that the vehicle’s battery is
charged, properly connected, not dam-
aged and cellular and GPS coverage is
available.Tightening torque
Force times lever arm (e.g. a lug
wrench) with which threaded fasteners
such as wheel bolts are tightened.
Tire speed rating
Part of tire designation; indicates the
speed range for which a tire is ap-
proved.
Traction
Force exerted by the vehicle on the
road via the tires.VIN
(V
ehicle I
dentification N
umber)
The number set by the manufacturer
and placed on the body to uniquely
identify each vehicle produced.
Voice control system*
Voice control system for car phones,
portable cell phones and audio sys-
tems (radio, CD, etc.).

352 IndexTelephone
Emergency call 179
Telephone* 24, 200
Answering a call 128
Dialing a number from the phone book
128
Ending a call 128
Hands-free microphone 26
Loading phone book* 128
Messages in display 269
Operating 126
Operation 176
Redialing 129
Temperature
Display mode 117
Grades of tires 326
Setting interior temperature 145
Setting units in display 117
Tires 235
Tightening torque 331
Tightening torque (Wheel bolts) 291
Tilt
Backrest 33
Head restraint 34
Seat cushion 33Time
Setting hours 116
Setting minutes 116
Time display
Setting 117
Tire inflation pressure
Checking 225, 234
Tire speed rating 219, 331
Tire traction 219
Tires 233, 311
Collapsible 328
Consumer information 325
Direction of rotation 234
Driving instructions 218
Retreads 233
Rims and tires 311
Service life 234
Temperature 235
Temperature grades 326
Tread depth 236
Wear pattern 235
Winter 236
Tools 272
Tow-away alarm 25, 79
Arming 79
Disarming 79Disarming for transport 79
Towing eye bolt (vehicle tool kit)
Installing 302
Towing the vehicle 299
Tracking services
For stolen vehicle 209
Traction 136, 325, 331
Transmission see
Automatic transmission 229
Transmission selector lever 277
Unlocking manually 277
Tread depth (tires) 236
Treadwear 325
Trim panel
Opening 304
Trip computer 125
Trip odometer
Resetting 103
Trunk
Auxiliary fuse box 304
Lighting 101
Trunk lid 85
Trunk lid
Closing 86
Emergency release 86
Opening 85

354 IndexVehicle tool kit 272
Alignment bolt 272
Spare fuses 272
Special fuse puller 272
Towing eye bolt 272
Vehicle jack 272
Wheel bolts 272
Wheel wrench 272
Vehicle washing 242
Ventilated storage compartment 148
Ventilation
Storage compartment 148
VIN (Vehicle Identification Number) 308,
331
Voice control system* 331
Voice recognition system*
Hands-free microphone 26
W
Warning sounds
Drivers seat belts 62
Parking brake 46
Warranty coverage 307
Washer fluid see Windshield washer fluid
Washing the vehicle 240
Wear pattern (tires) 235
Weights 316Wheel change
Tightening torque 291
Wheels
Rotating 235
Tires and wheels 233
Window curtain airbags 61
Windows see Side windows
Windshield
Defogging 145, 153
Refilling washer fluid 232
Replacing wiper blades 287
Washer fluid 232, 324
Washer system 324
Windshield washer fluid 324
Message in display 270
Mixing ratio 324
Refilling 232
Wiping with 49
Windshield washer system 324
Windshield wipers 48
Fast wiper speed 48
Replacing wiper blades 287
Single wipe 49
Switching on 48
Wiping with windshield washer fluid 49Winter driving 236
Block heater 237
Snow chains 237
Tires 236
Transmission program mode 136
Winter driving instructions 220
Winter tires 236
Wiper blades
Cleaning 243
Installing 287
Removing 287
Removing insert 287
Replacing 287
Wiping
And washing simultaneously 49
Interval 48
With windshield washer fluid 49
X
Xenon headlamps
Bi-Xenon 327