
The physical principles of a frontal collision are simple. Both the moving vehicle and the passenger
possess energy ⇒ fig. 68, which varies with vehicle speed and body weight. Engineers call this energy
“kinetic energy.”
The higher the speed of the vehicle and the greater the vehicle's weight, the more energy has to be
“absorbed” in a crash.
Vehicle speed is the most significant factor. If your speed doubles (for example, from 15 mph to
30 mph - 25 km/h to 50 km/h), the energy increases 4 times!
Because the occupants of the vehicle in the above example are not using safety belts, they are not
“attached” to the vehicle. In a frontal collision, they will keep moving at the same speed the vehicle
was moving just before the crash, until something stops them - here, the inside of the passenger
compartment. Because the occupants of the vehicle in the example are not wearing safety belts, their
entire kinetic energy will be absorbed by impact with the wall ⇒ fig. 69.
The same principles apply to people in a vehicle that is in a frontal collision on the highway. Even at
city speeds of 20–30 mph (30–50 km/h), the forces acting on the body can reach one ton (2,000 lbs or
1,000 kg) or more. At greater speeds, these forces are even higher.
Of course, the laws of physics don't apply just to frontal collisions; they determine what happens in all
kinds of accidents and collisions.
What happens to passengers not wearing a safety belt
Fig. 70 The unbelted driver is thrown forward.
Fig. 71 Unbelted passengers in the rear seats are thrown forward on top of the belted driver.

the front seat is occupied and the safety belt is not being used will signal the airbag control unit during
a collision that the front passenger seat is occupied and that the safety belt is being used. The elec-
tronic control unit for the airbag system will then receive incorrect information that will cause the safety
belt pretensioner to deploy unnecessarily and the front passenger airbag to deploy later in collisions
that would normally trigger the front airbag earlier in the collision to help protect an unrestrained front
seat occupant. The airbag will not be able to provide enough protection for an occupant not wearing a
safety belt.
x Only use the safety belt extender approved by Volkswagen for your vehicle.
WARNING
Improper use or positioning of a safety belt extender increases the risk of serious personal
injury and death.
x A driver or passenger who is not properly restrained can be seriously injured by striking
the interior of the passenger compartment or by the safety belt itself, which can be displaced
from stronger parts of the body into sensitive areas like the abdomen.
x Safety belt extenders offer optimum protection only when they are properly used.
x Only use the extender when the belt is not long enough to be worn low and snug and the
person is in the correct seating position. Remove and stow extender safely when not needed.
x Always make sure the safety belt tongue of the safety belt extender is securely inserted
into the buckle for the seating position that belongs to the seat where the safety belt extender
is being used. Attaching the safety belt to the wrong buckle will reduce safety belt effective-
ness and can cause serious personal injury.
x Never use the safety belt extender if you can properly attach the safety belt without it.
Using a safety belt extender when not needed can increase the risk of injury, especially in a
collision.
x Never use a safety belt extender if the distance (B) between the front edge of the safety
belt extender buckle (A) and the centerline of the person using the safety belt extender
⇒ fig. 81 (C) is less than 6 inches (15 cm).
x Never leave a safety belt extender attached to the vehicle safety belt buckle when the
extender is not needed and being used with the safety belt. Otherwise, the airbag control
module will receive an incorrect signal from the safety belt buckle and this will prevent the
airbag from working properly for a person who is not using the safety belt.
x Never use more than 1 extender with a safety belt. Using more than 1 extender can change
the way the safety belt passes over the body and can cause serious injury.
x Never use the safety belt extender to secure a child restraint.
x Never use a safety belt extender on your Volkswagen that you got from another automo-
bile manufacturer or from an automotive parts store.
x Never use the safety belt extender you got for your vehicle for any other vehicle, regard-
less of make, model, or model year.
NOTICE
x Leaving the extender attached to the safety belt buckle when the front seat is occupied and the
safety belt is not being used will signal to the airbag control unit that the front passenger seat is occu-
pied and that the safety belt is being used. The electronic control unit for the airbag system will then
receive incorrect information that will
– cause the safety belt pretensioner to deploy unnecessarily in collisions
– cause the front passenger airbag to deploy later in collisions in which the front airbag
would otherwise be triggered earlier to help protect an unrestrained front seat passenger.
x A pretensioner that has deployed cannot be repaired. The entire safety belt must be re-
placed.