212 Driving and operatingTrailer hitchGeneral informationOnly use towing equipment that hasbeen approved for your vehicle.Vehicles with natural gas enginesrequire special towing equipment.Entrust retrofitting of towingequipment to a workshop. It may benecessary to make changes thataffect the cooling system, heatshields or other equipment.The bulb outage detection function fortrailer brake light cannot detect apartial bulb outage. E.g. in case of4x 5 Watt bulbs, the function onlydetects lamp outage when only asingle 5 Watt lamp remains or noneremain.Fitting of towing equipment couldcover the opening of the towing eye.If this is the case use the coupling ballbar for towing. Always keep thecoupling ball bar in the vehicle.Driving characteristics andtowing tipsBefore attaching a trailer, lubricatethe coupling ball. However, do not doso if a stabiliser, which acts on thecoupling ball, is being used to reducesnaking movements.For trailers with low driving stabilityand caravan trailers with a permittedgross vehicle weight of more than1300 kg the use of a stabiliser isstrongly recommended when drivingabove 50 mph.If the trailer starts snaking, drive moreslowly, do not attempt to correct thesteering and brake sharply ifnecessary.When driving downhill, drive in thesame gear as if driving uphill anddrive at a similar speed.Adjust tyre pressure to the valuespecified for full load 3 279.Trailer towingTrailer loadsThe permissible trailer loads arevehicle and engine-dependentmaximum values which must not beexceeded. The actual trailer load isthe difference between the actualgross weight of the trailer and theactual coupling socket load with thetrailer coupled.The permissible trailer loads arespecified in the vehicle documents. Ingeneral, they are valid for gradientsup to max. 12 %.The permitted trailer load applies upto the specified incline and up to analtitude of 1000 metres above sealevel. Since engine power decreasesas altitude increases due to the airbecoming thinner, therefore reducingclimbing ability, the permissible grosstrain weight also decreases by 10 %for every 1000 metres of additionalaltitude. The gross train weight doesnot have to be reduced when drivingon roads with slight inclines (less than8 %, e.g. motorways).
