More & Better Safety Features

More & Better Safety Features

by -

Safety has always been the most noted feature of Volvos and something which many people have bought the Swedish cars for. So it’s hardly surprising that with the new S40/V40, Volvo has put in new features that position the models at the top of their segment in safety. The safety cage for the occupants incorporates the Side Impact Protection System (SIPS), a structural design which offers a high degree of protection by dissipating impact energy through the structure. The front and rear members also help to dissipate the force of collisions in a programmed manner.

New to the latest generation are dual-stage airbags (plus sidebags) for both front occupants and the inflatable curtain (IC) which is already available in the S80. The S40/V40 are the only cars in their segment to have the IC feature.

The dual-stage airbags are an innovation in these supplementary restraint systems and rely on the severity if the impact rather than absolute speed to deploy. At low impact energy levels (starting from around 3g), the inflation will be only 70% of the maximum volume so that the passengers do not experience severe discomfort from the high-speed ‘punch’. However, if the impact energy is high, then the airbags will deploy to 100% of their volume. This means they will be harder but the hardness is necessary since the passengers will be thrown forward with greater force and therefore need stronger cushioning.

According to Mr Campman, the systems function more intelligently now and will, in some situations, not deploy because they are not really needed. This will save owners money besides the trauma of having an airbag inflate in their faces. Mr Campman said that Volvo’s studies of airbag usage over two decades has shown that the airbags do not deteriorate during ten years. After that time, it is recommended that they be checked.

“The electronic systems are reliable enough and there is a constant circuit check while the car is being driven,” he explained. “The checking occurs approximately every 10 seconds and if anything is not operating properly, the driver will be warned right away by a lamp on the instrument panel.”

The IC is a safety innovation which is regarded as an extension of SIPS. Concealed in the liner just above the windows, the IC will inflate within 25 milliseconds to cover the window openings front and rear. It is supposed to be in place before the occupant’s head can hit the side of the car or the window area, thus reducing injuries. Tests have shown that as much as 75% of the force generated by the head being suddenly thrown sideways in a side collision can be absorbed by the IC. Furthermore, in the event that the glass breaks, the IC will prevent ejection.

The front seats, redesigned for better support and comfort, have WHIPS – the Whiplash Protection System. WHIPS is claimed to reduce whiplash injuries (resulting in neck injuries) by lowering g-forces by 50% through allowing movement of the seat in such a way as to match the body recoil during a rear-end collision. It is most effective at speeds between 15 and 30 km/h.

Active safety systems are also superior in these Volvos with standard ABS and Electronic Brake Force Distribution (EBD). EBD works with ABS to maximise braking efficiency by increasing brake force on the rear brakes even during conditions where the rear end lightens as the car is braked hard. This promotes stability on all surfaces and even in cornering, EBD can adjust rear braking force dynamically to the loading.

Also included with the cars sold in Malaysia is the Dynamic Stability Assistance (DSA) system which is a sort of traction control system. DSA can react within 25 milliseconds, corresponding to 0.6 metres at 90 km/h, to restore traction on a front wheel that loses grip on a slipper surface. It does so by reducing engine torque, rather than by using the brakes, in stages till grip is recovered. Once grip is achieved again, the engine torque level is normalised within 20 milliseconds.

DSA operates at all speeds and according to Mr Campman, even in reverse! It allows the car to be driven with a greater margin of safety without skidding. However, it does not work for starting off on slippery surfaces; that can be done by using the Winter mode on the automatic transmission which induces moving off with a higher gear to minimise wheelspin.


Leave a Reply