Glossary: Key technical terms

Nov 30, 2016

Car2Car crashes: Crash test configurations where vehicles do not collide with barriers, but with each other. In keeping with its safety philosophy of "Real Life Safety", Mercedes-Benz has for many years examined the accident compatibility of different road users in such Car2Car crash tests.

Car-to-X communication: Car-to-X technology allows the exchange of information between vehicles, as well as between vehicles and the transport infrastructure. This means that advance notification of potential hazards is given to drivers, allowing them to ready themselves accordingly and if possible prevent critical situations from occurring in the first place.

Crash test: Test in which the deformation behaviour of a vehicle is examined during different types of collision, e.g. frontal, side or rear impact and rollovers.

Roof-drop test: In-house Mercedes-Benz crash test. The vehicle body falls from a height of 50 centimetres and at a slight incline onto the roof structure, so that initially only one of the two A-pillars is affected. In this load case the test regulation only allows defined plastic deformation in order to maintain the protective area.

Dummy: Life-size doll fitted with measuring technology, used in crash tests to simulate the loads acting on the human body during an accident.

Normal g force: The acceleration experienced by a solid body on the earth's surface.

Euro NCAP (European New Car Assessment Programme): A consortium that has been conducting crash tests since 1997. At present twelve institutions (ministries of transport, automobile clubs, insurance associations and research institutes) from eight European countries participate in this programme. New vehicles are assessed using a star-rating system.


"Fishhook" test: Evasive manoeuvre with a body roll test to assess the risk of a rollover. The Fishhook test can be automated in the TFS.

Compatibility: Relative vulnerability of different road users in Car2Car crashes. Smaller, lighter vehicles are at a physical disadvantage owing to the unequal mass ratio. In the event of a collision with a heavier vehicle, this can lead to high rates of deceleration. Mercedes-Benz always designs the body structure of large vehicles so that they are able to reduce the loads acting on smaller, lighter vehicles without compromising their own occupant protection.

Offset crash: Crash test configuration in which the vehicle only impacts an obstacle (vehicle or barrier) with part of its front section. Mercedes-Benz introduced the offset crash as a realistic in-house test method in 1979, on the basis of accident research findings. Today it is well-established as a worldwide legal requirement.

Post impact test: A special side impact configuration. The test vehicle is driven sideways into a steel pillar on a test sled. The impact occurs at the head level of an adult dummy on the driver's seat. The resulting loads on e.g. the head, ribcage, abdomen, chest area and pelvis are measured and assessed.

"Real Life Safety" philosophy: On its way towards accident-free driving, Mercedes-Benz always takes its lead from what happens in real accidents, so as to protect all road users.

Rollover test: Crash test configuration in which the vehicle rolls over. The rollover test according to FMVSS208 is a legal requirement. The vehicle is mounted on a sled at an angle of 23° to the Y-axis and braked from 48.3 km/h. The vehicle is thrown off the sled and rolls over. Mercedes-Benz also uses inclined ramps to carry out rollover tests.


Sled test: In this crash simulation a test sled is hydraulically or electrically accelerated and braked. A test object (vehicle bodyshell or assembly) is mounted on the sled and subjected to the forces arising during a real vehicle crash. Sled tests enable individual components or systems to be tested without destroying a vehicle.

Small overlap test: Crash test with a small overlap (e.g. 25 %) where e.g. only the width of a car's headlamp impacts a fixed obstacle.