2009 Mercury Mariner Owner's Manual - Page 158

Tires, Wheels and Loading Power is supplied to all four wheels through a transfer case or power transfer unit. 4WD vehicles allow you to select different drive modes as necessary. Information on transfer case operation and shifting procedures can be found in the Driving chapter. Information on transfer case maintenance can be found in the Maintenance and Specifications chapter. You should become thoroughly familiar with this information before you operate your vehicle. On some 4WD models, the initial shift from two-wheel drive to 4WD while the vehicle is moving can cause a momentary clunk and ratcheting sound. These sounds are normal as the front drivetrain comes up to speed and is not cause for concern. WARNING: Do not become overconfident in the ability of 4WD and AWD vehicles. Although a 4WD or AWD vehicle may accelerate better than two-wheel drive vehicle in low traction situations, it won't stop any faster than two-wheel drive vehicles. Always drive at a safe speed. How your vehicle differs from other vehicles SUV and trucks can differ from some other vehicles in a few noticeable ways. Your vehicle may be: • Higher - to allow higher load carrying capacity and to allow it to travel over rough terrain without getting hung up or damaging underbody components. • Shorter - to give it the capability to approach inclines and drive over the crest of a hill without getting hung up or damaging underbody components. All other things held equal, a shorter wheelbase may make your vehicle quicker to respond to steering inputs than a vehicle with a longer wheelbase. 158 2009 Mariner (mrn) Owners Guide, 2nd Printing USA (fus)