2007 BMW X5 Owner's Manual - Page 125

Hydroplaning When driving on wet or slushy roads, reduce road speed. If you do not, a wedge of water can form between tires and road surface. This phenomenon is referred to as hydroplaning, and is characterized by a partial or complete loss of contact between the tires and the road surface, ultimately undermining your ability to steer and brake the vehicle.< The risk of hydroplaning increases as the tread depth of the tires decreases, refer also to Minimum tread depth on page 219. Do not drive with your foot resting on the brake pedal. Even light but consistent pedal pressure can lead to high temperatures, brake wear and possibly even brake failure.< Driving in wet conditions When roads are wet or there is heavy rain, briefly exert gentle pressure on the brake pedal every few miles. Monitor traffic conditions to ensure that this maneuver does not endanger other road users. The heat generated in this process helps dry the pads and rotors to ensure that full braking efficiency will then be available when you need it. Controls Reference Mobility Communications Entertainment Navigation Driving tips Driving through water Do not drive through water on the road if it is deeper than 20 in/50 cm, and then only at walking speed at the most. Otherwise, the vehicle's engine, the electrical systems and the transmission may be damaged.< Hills To prevent overheating and the resulting reduced efficiency of the brake system, drive long or steep downhill gradients in the gear in which the least braking is required. Even light but consistent pressure on the brake pedal can lead to high temperatures, brake wear and possibly even brake failure.< The braking effect of the engine can be further increased by downshifting in the manual mode of the automatic transmission, if necessary into first gear, refer to page 61. This prevents an excessive strain on the brakes. Do not drive in idle or with the engine stopped, otherwise there will be no engine braking action or support of the braking force and steering. Never allow floor mats, carpets or any other objects to protrude into the area of movement of the pedals and impair their operation.< Starting assistant The starting assistant enables you to start off conveniently on slopes. The parking brake is not required for this purpose. 1. Hold the vehicle with the footbrake. 2. Release the footbrake and immediately drive off quickly. The starting assistant holds the vehicle for approx. 2 seconds after releasing the footbrake. Depending on the load, the vehicle may also roll back slightly during this time. After releasing the footbrake, immediately start quickly, otherwise the starting assistant no longer holds the vehicle after approx. 2 seconds and it begins to roll back.< Braking safely Your BMW is equipped with ABS as a standard feature. In situations that require it, it is best to brake with full force. Since the vehicle maintains steering responsiveness, you can still avoid possible obstacles with a minimum of steering effort. Pulsation of the brake pedal, combined with sounds from the hydraulic circuits, indicate that ABS is in its active mode. Corrosion on brake rotors When the vehicle is driven only occasionally, during extended periods when the vehicle is not used at all, and in operating conditions where brake applications are less frequent, there is an increased tendency for corrosion to form on rotors, while contaminants accumulate on the brake pads. This occurs because the minimum pressure which must be exerted by the pads during brake applications to clean the rotors is not reached. 123 Online Edition for Part no. 01 41 0 012 501 - © 08/06 BMW AG At a glance