Join the Car Talk Community!  It's this neighbor of mine see The
guy always makes...  Dear Tom and Ray:  It's this neighbor of
mine, see. The guy always makes wild statements after we put a
can of beer in his hands. This time he was after the snow chain
manufacturers, claiming they make a bundle, unnecessarily,
because a regular car is only driven by one wheel, not two. So,
he says, one chain would be enough. Is this guy right? And if he
is, is four wheel drive really two wheel drive? We finally got
him to shut up, but he'll be back, so please help us.   RAY: Hey
Albert, have you ever heard the expression "a little knowledge
is a dangerous thing?" Well, we'll add a corollary to that: A
little knowledge and a can of beer is an extremely dangerous
thing.  TOM: Under normal circumstances, a two-wheel-drive car
is a two-wheel-drive car. That is, power is distributed more-or-
less equally to the rear wheels.  RAY: In between the wheels is
something called a "differential," which adjusts the amount of
power sent to