04.Jargon buster
Braking systems
Antilock brakes (ABS) operate during heavy braking and on slippery roads, to stop the wheels from locking up. ABS allows the driver to steer and gain control of the car without skidding or spinning out of control. It is also referred to as ALB.
Electronic brake-force distribution (EBD) helps to balance braking forces between the front and rear wheels. It varies the amount of force which is applied to individual brakes, taking into account road conditions, speed, load and other factors.
Traction control prevents wheel spin and maintains vehicle stability during acceleration, when too much power is applied. It is particularly useful during wet conditions, when the road is slippery or when rapid acceleration is required.
Electronic stability control (ESC) builds on ABS, EBD and traction control, and also works to control loss of traction during cornering. It is an advanced technology aimed at preventing crashes and providing help when turning under particularly hazardous conditions. ESC compares the driver's steering wheel position to the direction of travel of the vehicle. When a difference is detected by the system, ESC intervenes to independently apply the brakes to individual wheels. This allows the driver to maintain control of the vehicle. ESC is also referred to as:
- Electronic stability program
- Vehicle stability control
- Dynamic stability control
- Vehicle stability assist
Other safety features
Seat belt pretensioners tighten up any slack in the belt webbing in the event of a crash. This helps to hold the occupant secure and move them into the optimum crash position.
Active head restraints are situated on the head rest of the seat and during a rear-end crash move forward and up to automatically decrease the space between the restraint and the occupant's head. This reduces the degree to which the head accelerates before making contact with the restraint.
Seat belt reminders are visual and/or audible warning devices used to alert vehicle occupants that a seat belt is not being worn.
Three-point seat belts are one single continuous length of webbing that spreads the impact forces more evenly across the passenger's torso and helps to keep the upper body in place in the event of a collision.
Airbags are large nylon bags that inflate and deflate rapidly in the event of a severe frontal or side crash. Sensors are fitted at different points of the car and detect when a crash occurs. When the sensors all agree that the airbags should be deployed the system triggers an inflator and igniter unit. The airbags inflate, splitting open the covers on the steering wheel or dash board, causing them to balloon in front of the occupant. As the occupant's head strikes the airbag, it starts deflating. Vehicles can come with, front, side, head and knee airbags.
Hybrid technology
Hybrid cars use a conventional petrol engine with an additional electric power plant. They're designed to be more fuel-efficient while still providing the performance and efficiency of a petrol-fuelled car. Hybrids are most efficient in city driving situations; at low speeds the petrol engine stops and the battery kicks in to keep the car running. On the open road, the difference between hybrid and petrol-fuelled cars is not as noticeable. The petrol engine on a hybrid will shut down if you're travelling downhill on freeways and open roads; however, a hybrid acts like any other car when travelling uphill.