Your Landcruiser is 4WD but it is always engaged through a center differential. When in low or with the "center diff lock" button depressed the center diff locks for better traction. Many 4WD vehicles only have a front and rear diff so you drive around town in 2WD and when you need it you shift into 4WD but b/c they don't have a center diff the front and rear axles are locked together so you only want to use it on soft/slippery surfaces like sand/mud/snow/ice. If used on hard surfaces some wheels will need to slip to allow the vehicle to turn and its rough on the mechanicals.

The Landcruiser has the added benefit of having front & rear locking diffs on the 80 series when the going gets rough. If you lock down the front and rear diffs it is extremely difficult to steer b/c all 4 wheels are lock together and there is absolutely no slip to allow for turning. All 4 wheels are getting exactly the same amount of torque. At this point all you need is one wheel with traction to keep moving (in theory)!

The MB G-wagen is similar to the 80 series with a solid front axle and 3 lockable diffs. Either one of these machines is your best bet offroad stock out-of-the-box. The newer Landcruisers (100 series since 1998) use an independent front suspension which is less desirable offroad. In markets other than the US Toyota offers a 105 series which is the newer better 100 series body on top of the older better 80 series suspension with a solid front axle. Best of both worlds but apparently not needed for the US "Mall Cruiser" market.

More than you wanted to know.

Randy
'94 E500
'94 Landcruiser FJZ80
'00 S500