Seat belts
Physical principles of a frontal colli-
s ion Fig. 76
A driver not wearing a seat belt is
thr o
wn f
orward violently Fig. 77
The unbelted passenger in the rear
se at
i
s thrown forward violently, hitting the
driver wearing a seat belt It is easy to explain how the laws of physics
w
ork
in the c
ase of a head-on collision: when
a vehicle starts moving, a type of energy called “kinetic energy” is created both in the
pas
sengers and inside the vehicle.
The amount of “kinetic energy” depends on
the speed of the vehicle and the weight of
the vehicle and its passengers. The higher
the speed and the greater the weight, the
more energy there is to be “absorbed” in an
accident.
The most significant factor, however, is the
speed of the vehicle. If the speed doubles
from 25 km/h (15 mph) to 50 km/h
(30 mph), for example, the corresponding ki-
netic energy is multiplied by four.
Because the vehicle occupants in our exam-
ple are not restrained by seat belts, in the
event of crashing against a wall, all of the oc-
cupants' kinetic energy will be absorbed
solely by said impact.
Even at speeds of 30 km/h (19 mph) to
50 km/h (30 mph), the forces acting on bod-
ies in a collision can easily exceed one tonne
(1000 kg). At greater speed these forces are
even higher.
Vehicle occupants not wearing seat belts are
not “attached” to the vehicle. In a head-on
collision, they will move forward at the same
speed their vehicle was travelling just before
the impact. This example applies not only to
head-on collisions, but to all accidents and
collisions. Even at low speeds the forces acting on the
body in a co
llision are so great that it is not
possible to brace oneself with one's hands.
In a frontal collision, unbelted passengers
are thrown forward and will make violent con-
tact with the steering wheel, dash panel,
windscreen or whatever else is in the way
››› Fig. 76.
It is also important for rear passengers to
wear seat belts properly, as they could other-
wise be thrown forward violently through the
vehicle interior in an accident. Passengers in
the rear seats who do not use seat belts en-
danger not only themselves but also the front
occupants ››› Fig. 77.
63
Technical data
Advice
Operation
Emergencies
Safety
Wheels and tyres
Unusual vibration or the car pulling to one
s ide m
a
y indicate that one of the tyres is
damaged. Reduce speed immediately and
stop if you suspect that a wheel may have
been damaged! Check the tyres for damage
(blisters, cracks, etc.). If no external damage
is visible, drive slowly and carefully to the
nearest Official Service and have the vehicle
inspected.
Changing wheels Fig. 215
Interchanging tyres. Changing wheels around
If
the w
e
ar is visibly greater on the front tyres,
they should be exchanged for the rear tyres
as shown in the diagram ››› Fig. 215. All the
tyres will then last for about the same time.
To ensure that the wear is equal on all tyres
and maintain their optimum useful life, they
should be changed around every 10 000 km. Storing tyres
When you r
emove the tyres, mark them in or-
der to maintain the same direction of rotation
when they are installed again.
When removed, the wheels and/or tyres
should be stored in a cool, dry and preferably
dark location. Store tyres in a vertical posi-
tion, if they are not fitted on wheel rims.
New tyres or wheels All four wheels must be fitted only with tyres
of
the s
ame type, s
ize and the same tread
pattern.
The correct tyre/wheel combinations speci-
fied for your vehicle are listed in its docu-
mentation.
Note for Italy: A SEAT Service Centre should
be consulted whether different sized wheels
or tyres to those originally fitted by SEAT may
be fitted, as well as the combinations al-
lowed between the front axle (axle 1) and
back axle (axle 2).
Understanding the tyre designations makes
it easier to choose the correct tyres. The tyre
designation is marked on the sidewall. For
example.
195/55 R 15 85 H
This contains the following information:
195Tyre width in mm
55Height/width ratio in %
Ridentifying tyre construction letter –
Radial
15Rim diameter in inches
85Load rating code
HSpeed rating code letter The tyres are subject to the following
maxi-
mum s
peed limits:
Speed rating codeletterMaximum speed limit
Q160 km/h (99 mph)
R170 km/h (106 mph)
S180 km/h (112 mph)
T190 km/h (118 mph)
U200 km/h (124 mph)
H210 km/h (130 mph)
V240 km/h (149 mph)
W270 km/h (168 mph) The m
anufacturing date is also indicated on
the ty r
e sidewall (possibly only on the inner
side of the wheel).
DOT … 27 12… »
217
Technical data
Advice
Operation
Emergencies
Safety
