4wd vs awd

[Lee M. Levitt]

Robert Turlington <rturlington at qwest.net> writes:
>
> I all ways thought, and please correct me if I'm wrong:
>
> 4wd:  Is for off road use only and forces the front
> wheels to turn at the same speed as the back wheels.  This causes
excessive wear
> on tires, drive, and steering components on dry pavement

Almost. Many 4wd systems have this problem, felt when 4wd is engaged and you
try to take a slow sharp turn, in the form of kickback through the steering
wheel. On dirt/gravel/mud/snow/etc, the inside front wheel will slip, but on
pavement it grips too well and you feel it in the steering wheel.

On the other hand, some permanent 4wd systems are designed to be driven both
on and off road. My Range Rover, for instance, had a viscous center diff
that kept this from happening. You can take this vehicle (or a Discovery, or
a LandCruiser, or many other newer vehicles with permanent 4wd systems) from
the autocross circuit to the highway to the trail without ever adjusting or
changing anything.

The key is that if you *can* switch in and out of 4wd, you should use it
offroad and in sloppy weather. If you *can't* switch in and out (like on the
Range Rover), there's probably a center diff that keeps the kickback from
happening.

Lee
'95.5 S6 avant
'96 A6 quattro avant