Uncompromising safety standards were given top priority in the development of MINI Cooper and MINI One. BMW Group quality and manufacturing standards were strictly applied.
MINI Cooper and MINI One have disc brakes all round, ventilated at the front. The front disc brakes measure 276 x 22 mm; those at the rear are 259 x 10 mm. The braking system, with a diagonal dual-circuit arrangement, includes four-sensor ABS, electronic braking distribution (EBD) and cornering brake control (CBC) as standard.
The EBD system controls the distribution of the hydraulic braking force between the front and rear wheels, ensuring the optimum braking power distribution between axles at all times and under different load conditions. If the car's rear axle is under heavy loading, a higher braking force than normal can be safely applied to the rear wheels, greatly improving the vehicle's braking abilities. The EBD mechanism is automatically activated under average braking pressure, long before the ABS would be required. The driver cannot deactivate it.
In addition, both MINI Cooper and MINI One are fitted with CBC (Cornering Brake Control). CBC tempers the natural tendency for a car to become unstable at the rear if the brakes are applied heavily while cornering. The system recognizes that the car is cornering and feeds more braking force to the outside front wheel and counteracts potential oversteer. This also means that more braking force can be fed to the rear brakes and the car is slowed down as fast as possible with maximum stability.
As an option, MINI Cooper and MINI One can be fitted with disconnectable ASC+T (Automatic Stability Control plus Traction), which effectively prevents front wheel spin and guarantees stability. This smart electronic system uses the ABS sensors to detect any wheel slippage. When the system does so it automatically cuts power to the spinning wheel until it grips again.
It also works under deceleration on a slippery surface, if a wheel approaches lock-up due to engine braking. In this instance power is gently fed to that wheel to get it rolling again and so control is regained. A warning light comes on when the system is activated.
Dynamic Stability Control (DSC) will also be available as an option. DSC is an expansion of ABS and ASC + T. DSC monitors lateral and longitudinal forces on the car as well as throttle and steering inputs from the driver and any wheel slippage. Thus it determines the intended trajectory of the car and compares it to its actual course. If necessary, it can adjust the dynamic attitude of the car by applying braking forces to individual wheels and controlling throttle inputs.
If it detects oversteer, DSC applies the brake to the outer front wheel. If the driver is already braking, the computer increases the braking pressure on this wheel and reduces the pressure on the inside wheels. In the case of an understeer, DSC applies braking force to the rear wheel on the inside of the bend. If the driver has already started braking, the braking pressure on the wheel on the inside of the curve is increased, whilst the pressure on the outer wheels is reduced.
MINI Cooper and MINI One are the first vehicles in this segment to be fitted as standard with a tire pressure warning indicator. This means that the driver can react to a loss of pressure before the tire is damaged and before the loss of pressure becomes a danger. As approximately 80 per cent of all blow-outs can be detected before the tire bursts, the system is a valuable safety feature.
It works on the following principle: if there is a loss of air pressure, the rolling radius of the tyre is reduced. As a result, the speed at which this wheel rotates increases. The system measures the number of times the wheel turns via the sensors in the 4-sensor-ABS system, carries out a comparison with the diagonally opposite wheel and compares the average speeds. A light then comes on in the speedometer display to tell the driver that the pressure is falling in one of the
Because major damage to tires following an unnoticed loss of pressure can be avoided, the MINI MS (MINI Mobility System) is provided in the boot instead of a spare wheel. This system consists of a sealant and a compressor that can be attached to the in-car power socket. Once tire pressure loss is detected, the tire can be repaired in a few easy steps and pumped back up again, allowing the driver to travel home or to the nearest garage. Alternatively, an emergency space-saver spare wheel is offered as an option.
In addition, run flat tires are standard on the optional 16" or 17" wheels, again, setting new standards of active safety in the class. These tires have reinforced side walls and are made from heat-resistant rubber. Functions such as ABS, ASC + T or DSC are not affected if pressure is lost from these tires. The driver can therefore continue his journey at a maximum speed of approximately 50 mph (80 km/h).
The MINI also sets new standards of passive safety. Front driver and passenger "smart" airbags that detect the strength of the impact and the presence of a passenger come as standard, as do side airbags for driver and passenger. The two side airbags are concealed in the outer cushions of the front seats and effectively protect the driver and passenger against thoracic injury. All the airbags are linked and controlled via common crash sensors, guaranteeing optimum use of the airbags in any situation.
In addition, both MINI Cooper and MINI One can be fitted with the optional head airbag system (AHPS 2 = Advanced Head Protection System), providing both front and rear passengers with maximum protection against head injury. The system is concealed in the roof along the side wall, stretching from the A pillar to the C pillar and protects the head against forces from the side and against objects penetrating into the vehicle. In the event of an impact, the head airbag deploys between the occupant's head and the sidewall of the vehicle. Naturally, three-point safety belts offer protection for all four seats, with the front seats also being fitted as standard with
belt pre-tensioners and belt-force limiters.
Comprehensive passive safety depends on a comprehensive body structure. The rigidity of the body shell, at 24,500 Nm/degree, is two to three times higher than that of other small cars and means that if a torsional
force of 24,500 Newton meters was applied, the body itself would only
twist by one degree. This also reduces vibration in the body and
guarantees excellent handling in all conditions and with all driving
styles. The body structure also makes the passenger cell extremely tough
and special crumple zones absorb energy extremely effectively in the event
of an accident.
The relative positions of front seats and the transverse engine give optimum occupant protection. The body shell and the materials used ensure that the passenger area is protected, and wide, energy-absorbent zones stop objects from penetrating into the footwell. The front axle has been specifically designed to transmit impact energy away from the passenger cell and through the floor.