2011 Mercedes GL-Class Owner's Manual - Page 170

168 Driving tips Coasting with the engine switched off G Warning! There is no power assistance for the steering and the brake when the engine is not running. Steering and braking requires significantly more effort and you could lose control of the vehicle and cause an accident as a result. Do not turn off the engine while the vehicle is in motion. Driving and parking If the vehicle is mostly driven for short distances, it is possible that malfunctions may occur during the automatic cleaning of the diesel particle filter. This can lead to engine damage. Therefore, if you frequently drive short distances, make sure to drive on highways or country roads for 20 minutes at least every 500 km. Brakes Important safety notes G Warning! On slippery road surfaces, never downshift in order to obtain braking action. This could result in drive wheel slip and reduced vehicle control. Your vehicle's ABS will not prevent this type of control loss. Do not engage the transfer case in position LOW when driving on ice or packed snow. At speeds below 18 mph (30 km/h) vehicle steering is adversely affected by the Off-road ABS. Exhaust check G Warning Inhalation of exhaust gas is hazardous to your health. All exhaust gas contains carbon monoxide (CO), and inhaling it can cause unconsciousness and possible death. Do not run the engine in confined areas (such as a garage) which are not properly ventilated. If you think that exhaust gas fumes are entering the vehicle while driving, have the cause determined and corrected immediately. If you must drive under these conditions, drive only with at least one window fully open at all times. G Warning Certain engine systems are designed to keep the level of poisonous components in exhaust fumes within legal limits. These systems only work optimally if they are maintained exactly in accordance with the manufacturer's specifications. For this reason, all work on the engine must be carried out by qualified and authorized MercedesBenz technicians. The engine settings must not be changed in any circumstances. Furthermore, all specific service work must be carried out at regular intervals and in accordance with the Mercedes-Benz service requirements. Details can be found in the Service Booklet. Make sure that you do not endanger other road users when you apply the brakes. Downhill gradients ! On long and steep gradients, you must reduce the cargo on the brakes by shifting to a lower gear in good time. This allows you to take advantage of engine braking and helps you to avoid overheating the brakes and wearing them out excessively. When you take advantage of engine braking, a drive wheel may not turn for some time, e.g. on a slippery road surface. This could cause damage to the drive train. Such damage is not covered by the Mercedes-Benz warranty. Engine oil ! Vehicles with a diesel particle filter: