
Vehicles traveling on a different line
DISTRONIC PLUS may not detect vehicles
traveling on a different line. The distance to
the vehicle in front will be too short.
Other vehicles changing lanes DISTRONIC PLUS has not detected the vehi-
cle cutting in yet. The distance to this vehicle will be too short.
Narrow vehicles DISTRONIC PLUS has not yet detected the
vehicle in front on the edge of the road, because of its narrow width. The distance to
the vehicle in front will be too short.
Obstructions and stationary vehicles
DISTRONIC PLUS does not brake for obsta-
cles or stationary vehicles. If, for example, the
detected vehicle turns a corner and reveals
an obstacle or stationary vehicle, DISTRONIC PLUS will not brake for these.
Crossing vehicles DISTRONIC PLUS may detect vehicles that
are crossing your lane by mistake. Activating
DISTRONIC PLUS at traffic lights with cross-
ing traffic, for example, could cause your vehi-
cle to pull away unintentionally. Driving systems
177Driving and parking Z

Regular checking of wheels and tires
G
WARNING
Damaged tires can cause tire inflation pres-
sure loss. As a result, you could lose control of your vehicle. There is a risk of accident.
Check the tires regularly for signs of damage
and replace any damaged tires immediately.
R Regularly check the wheels and tires of
your vehicle for damage at least once a
month, as well as after driving off-road or
on rough roads. Damage includes bulges
and deformation on tires, cuts, punctures,
cracks or severe corrosion on wheels, for
example. Damaged wheels can cause a
loss of tire pressure.
R Regularly check the tire tread depth and
the condition of the tread across the whole
width of the tire (Y page 307). In order to
inspect the inner side of the tire surface,
turn the steering wheel to full lock.
R All wheels must have a valve cap to protect
the valve against dirt and moisture. Do notinstall anything onto the valve other than
the standard valve cap or a valve cap
approved by Mercedes-Benz for your vehi-
cle.
Do not install anything onto the valve, such as tire pressure monitoring systems.
R You should regularly check the pressure of
all your tires including the spare wheel, par- ticularly prior to long trips. Adjust the tire
pressure as necessary (Y page 314).
The service life of tires depends, among other things, on the following factors:
R Driving style
R Tire pressure
R Distance covered Tire tread
G
WARNING
Insufficient tire tread will reduce tire traction.
The tire is no longer able to dissipate water. This means that on wet road surfaces, the risk
of hydroplaning increases, in particular where speed is not adapted to suit the driving con-
ditions. There is a risk of accident.
If the tire pressure is too high or too low, tires
may exhibit different levels of wear at differ-
ent locations on the tire tread. Thus, you
should regularly check the tread depth and
the condition of the tread across the entire
width of all tires.
Minimum tire tread depth for:
R Summer tires: âin (3 mm)
R M+S tires: ãin (4 mm)
For safety reasons, replace the tires before
the legally prescribed limit for the minimum
tire tread depth is reached. Marking
:shows the tread wear indicator
(TWI). The arrow indicates the placement of
the tire tread.
Do not drive with tires which have too little
tread depth. tire traction on wet road surfaces decreases significantly when the tread depth
is less than 1
/ 8 in (3 mm).
Treadwear indicators (TWI) are required by
law. Six indicators are positioned over the tire
tread. They are visible once the tread depth is
approximately 1
/ 16 in (1.6 mm). If this is the
case, the tire is so worn that it must be
replaced.
The recommended tread depth for summer
tires is at least 1
/ 8 in (3 mm). The recommen-
ded tread depth for winter tires is at least 1
/ 6
in (4 mm). Operation
307Wheels and tires Z

are provided with the corresponding quality
grading markings on the sidewall of the tire.
Where applicable, the tire grading informa-
tion can be found on the tire sidewall between
the tread shoulder and maximum tire width.
Example:
R Treadwear grade: 200
R Traction grade: AA
R Temperature grade: A
All passenger car tires must conform to the
statutory safety requirements in addition to
these grades.
i The actual values for tires are vehicle-
specific and may deviate from the values in
the illustration. Treadwear
The treadwear grade is a comparative rating
based on the wear rate of the tire when tested under controlled conditions on a specified
U.S. government course. For example, a tire
graded 150 would wear one and one-half
times as well on the government test track as a tire graded 100.
The relative performance of tires depends
upon the actual conditions of their use, how-
ever, and may depart significantly from the
norm, due to variations in driving habits, ser-
vice practices and differences in road char-
acteristics and climate conditions. Traction
G
WARNING
The traction grade assigned to this tire is
based on straight-ahead braking traction
tests, and does not include acceleration, cor- nering, hydroplaning, or peak traction char-
acteristics.
! Avoid wheelspin. This can lead to damage
to the drive train. The traction grades, from highest to lowest,
are AA, A, B, and C. Those grades represent
the tire's ability to stop on a wet surface as
measured under controlled conditions on
specified government test surfaces of asphalt
and concrete. A tire marked C may have poor
traction performance.
The safe speed on a wet, snow covered or icy road is always lower than on dry road surfa-
ces.
You should pay special attention to road con-
ditions when temperatures are around freez-
ing point.
Mercedes-Benz recommends a minimum
tread depth of ãin (4 mm) on all four winter
tires. Observe the legally required minimum
tire tread depth (Y page 307). Winter tires can
reduce the braking distance on snow-covered surfaces in comparison with summer tires.
The braking distance is still much further than
on surfaces that are not icy or covered with
snow. Take appropriate care when driving.
Further information on winter tires (M+S
tires) (Y page 308). Temperature
G
WARNING
The temperature grade for this tire is estab-
lished for a tire that is properly inflated and
not overloaded. Excessive speed, underinfla-
tion, or excessive loading, either separately or
in combination, can cause excessive heat
build-up and possible tire failure.
The temperature grades are A (the highest), B,
and C. These represent the tire's resistance
to the generation of heat and its ability to dis- sipate heat when tested under controlled
conditions on a specified indoor laboratory
test wheel. Sustained high temperature can
cause the material of the tire to degenerate
and reduce tire life, and excessive tempera-
ture can lead to sudden tire failure. The grade
C corresponds to a level of performance
which all passenger car tires must meet under 320
Uniform Tire Quality Grading StandardsWheels and tires

the Federal Motor Vehicle Safety Standard
No. 109. Grades B and A represent higher
levels of performance on the laboratory test
wheel than the minimum required by law. Tire labeling
Overview of tire labeling
:
Uniform tire Quality Grading Standard
(Y page 325)
; DOT tire Identification Number
(Ypage 324)
= Maximum tire load (Y page 323)
? Maximum tire pressures (Y page 312)
A Manufacturer
B Tire material (Y page 324)
C Tire size designation, load-bearing capa-
city and speed rating (Y page 321)
D Load identification (Y page 323)
E Tire name
The markings described above are on the tire in addition to the tire name (sales designa-
tion) and the manufacturer's name.
i Tire data is vehicle-specific and may devi-
ate from the data in the example. Tire size designation, load-bearing
capacity and speed rating
G
WARNING
Exceeding the stated tire load-bearing capa-
city and the approved maximum speed could
lead to tire damage or the tire bursting. There is a risk of accident.
Therefore, only use tire types and sizes
approved for your vehicle model. Observe the
tire load rating and speed rating required for
your vehicle. :
Tire width
; Height-width ratio in percentage
= Tire code
? Rim diameter
A Load bearing index
B Speed rating
General: depending on the manufacturer's
standards, a letter is imprinted into the tire
wall before the size description.
If there is no letter preceding the size descrip-
tion (as shown above): these are passenger
vehicle tires according to European manufac-
turing standards.
If "P" precedes the size description:
passenger vehicle tires according to U.S.
manufacturing standards.
If "P" precedes the size description: light
truck tires according to U.S. manufacturing
standards.
If "T" precedes the size description: these are
compact emergency spare wheels at high tire Tire labeling
321Wheels and tires Z

pressure, to be used only temporarily in an
emergency.
Tire width: tire width:shows the nominal
tire width in millimeters.
Height-width ratio: height-width ratio;is
the ratio between tire height and tire width.
The aspect ratio is calculated by dividing the
tire width by the tire height. The resulting
quotient is given as a percentage.
Tire code: tire code=shows the tire type.
"R" represents radial tires; "D" represents
diagonal tires; "B" represents diagonal radial
tires.
Optionally, tires with a maximum speed of
over 149 mph (240 km/ h)may have "ZR" in
the size description, depending on the man-
ufacturer (e.g. 245/40 ZR 18).
Rim diameter: rim diameter?is the diam-
eter of the bead seat, not the diameter of the
rim flange. The rim diameter is specified in
inches (in).
The load-bearing index: load-bearing index
A (also load index), is a code that contains
the maximum load-bearing capacity of a tire.
Do not overload the tires by exceeding the
specified load limit. The maximum permissi-
ble load can be found on the vehicle's Tire and
Loading Information placard on the B-pillar on the driver's side (Y page 316).
Example:
Load-bearing index 91 indicates a maximum
load of 1,356 lb (615 kg) that the tires can
bear. For further information on the maximum tire load in kilograms and pounds, see
(Y page 323).
For further information on the load bearing
index, see "Load index" (Y page 323).
Speed rating: speed ratingBspecifies the
approved maximum speed of the tire.
i Tire data is vehicle-specific and may devi-
ate from the data in the example.
Regardless of the speed rating, always
observe the speed limits. Drive carefully and
adapt your driving style to the traffic condi-
tions. i
Since 2009, tires in Europe which corre-
spond to the noise limitations of Directive
ECE-R 117 show an >>S<< (Sound) mark.
This identification follows the type approval number and has no connection with the
speed rating.
Summer tires Index Speed rating
Q up to 100 mph (160 km/h)
R up to 106 mph (170 km/h)
S up to 112 mph (180 km/h)
T up to 118 mph (190 km/h)
H up to 130 mph (210 km/h)
V up to 149 mph (240 km/h)
W up to 168 mph (270 km/h)
Y up to 186 mph (300 km/h)
ZR...Y up to 186 mph (300 km/h)
ZR...(..Y) over 186 mph (300 km/h)
ZR over 149 mph (240 km/h)
R
Optionally, tires with a maximum speed of
over 149 mph (240 km/h) may have "ZR" in the size description, depending on the
manufacturer (e.g. 245/40 ZR18).
The service specification is made up of
load-bearing index Aand speed rating B.
R If the size description of your tire includes
"ZR" and there are no service specifica-
tions, ask the tire manufacturer in order to
find out the maximum speed.
If a service specification is available, the
maximum speed is limited according to the
speed rating in the service specification.
Example: 245/40 ZR18 97 Y.In this exam-
ple, "97 Y" is the service specification. The letter "Y" represents the speed rating and 322
Tire labelingWheels and tires

Maximum loaded vehicle weight
The maximum weight is the sum of:
R
the curb weight of the vehicle
R the weight of the accessories
R the load limit
R the weight of the factory installed optional
equipment
Kilopascal (kPa) Metric unit for tire pressure. 6.9 kPa corre-
sponds to 1 psi. Another unit for tire pressure
is bar. 100 kilopascals (kPa) are the equiva-
lent of 1 bar.
Load index In addition to the load-bearing index, the load
index may also be imprinted on the sidewall of
the tire. This specifies the load-bearing capa- city more precisely.
Curb weight The weight of a vehicle with standard equip-
ment including the maximum capacity of fuel,
oil and coolant. It also includes the air-condi- tioning system and optional equipment if
these are installed in the vehicle, but does notinclude passengers or luggage.
Maximum load rating The maximum load rating is the maximum
permissible weight in kilograms or lbs for
which a tire is approved.
Maximum permissible tire pressure Maximum permissible tire pressure for one
tire.
Maximum load on one tire Maximum load on one tire. This is calculated
by dividing the maximum axle load of one axle
by two. PSI (pounds per square inch) A standard unit of measure for tire pressure.
Aspect ratio Relationship between tire height and tire
width in percent.
Tire pressure This is pressure inside the tire applying an
outward force to each square inch of the tire's surface. The tire pressure is specified in
pounds per square inch (psi), in kilopascals
(kPa) or in bar. The tire pressure should only
be corrected when the tires are cold.
Cold tire pressure The tires are cold:
R if the vehicle has been parked without
direct sunlight on the tires for at least three
hours and
R if the vehicle has not been driven further
than 1 mile (1.6 km)
Tread The part of the tire that comes into contact
with the road.
Bead The tire bead ensures that the tire sits
securely on the wheel. There are several steel
wires in the bead to prevent the tire from
coming loose from the wheel rim.
Sidewall The part of the tire between the tread and the
bead.
Weight of optional extras The combined weight of those optional extras
that weigh more than the replaced standard
parts and more than 2.3 kg (5 lbs). These
optional extras, such as high-performance 326
Tire labelingWheels and tires

G 550
Vehicle length
183.5 in
(4662 mm) Vehicle width including
exterior mirrors
80.9 in
(2055 mm) Vehicle height
76.8 in
(1951 mm) Wheelbase
112.2 in
(2850 mm) Minimum ground clear-
ance
8.1 in
(205 mm) Turning radius
44.6 ft
(13.60 m) Gross vehicle weight rat-
ing (GVWR)
7054.8 lb
(3200 kg) Gross axle weight rating
(GAWR), front
3196.7 lb
(1450 kg) Gross axle weight rating
(GAWR), rear
4188.8 lb
(1900 kg) G 63 AMG
Vehicle length
187.8 in
(4769 mm) Vehicle width including
exterior mirrors
80.9 in
(2056 mm) Vehicle height
76.3 in
(1938 mm) Wheelbase
112.2 in
(2850 mm) Minimum ground clear-
ance
7.7 in
(196 mm) Turning radius
44.6 ft
(13.60 m) Gross vehicle weight rat-
ing (GVWR)
7054.8 lb
(3200 kg) G 63 AMG
Gross axle weight rating
(GAWR), front
3417.1 lb
(1550 kg) Gross axle weight rating
(GAWR), rear
4122.6 lb
(1870 kg) i
GVWR is the maximum permissible gross
weight of the vehicle. Gross vehicle weight (GVW) is the vehicle weight including fuel,
service products, spare wheel, accessoriesinstalled, load and, if applicable, trailer
drawbar load. The GVW must never exceed
the GVWR.
i The GAWR is the maximum permissible
axle weight. Vehicle data for off-road driving
Fording depth
! The depth of water must not exceed the
value specified in the table. Note that the
possible fording depth is less in flowing
water. The table shows fording depth
:when loa-
ded and ready to drive. Fording depth 24 in (60 cm)
For more information about off-road fording,
see (Y page 156). Vehicle data for off-road driving
345Technical data Z