The Hyperlogos

Toe is a measurement of the alignment of two wheels on the same [axle] (A literal axle between them is not necessary.) You have toe-in when the fronts are closer together, and toe-out when the rears are closer together. Observe the following (bad, soon to be replaced) diagram:

Toe Diagram

                     Front
   _                                       _
,-' \  <---------------X--------------->  / `-.
\    \                                   /    /
 \    \          X > Y = Toe Out        /    /
  \    \                               /    /
   \    \  <-----------Y----------->  /    /
    \    \                           /    /
     \,-'                             `-./


      _              Front              _
     / `-.                           _-' \
    /    /  <----------X---------->  \    \
   /    /                             \    \
  /    /          X < Y = Toe In       \    \
 /    /                                 \    \
/    /  <--------------Y-------------->  \    \
 `-./                                     \,-'

At nominal driving speeds, toe-in will produce [understeer] while cornering, since the inside tire will be pointing out of the turn, and toe-out will do the opposite. However, when you are driving hard, toe-in can actually increase [oversteer], because your outside wheel is most heavily [loaded], and the inside tire does not have as much traction. This tendency can be reduced by the use of a [sway bar], which minimizes [body roll], making the car dramatically more consistent.

Toe should be the last [alignment] setting you adjust, because both [camber] and [caster] will alter toe. Camber will not alter toe in a car with zero caster, but that is extremely rare.

Some cars also allow you to adjust the rear toe. Rear toe in makes the car more stable, and rear toe out makes the car turn more easily.

In general, you want no rear toe (most cars don't let you adjust it easily anyway) and only a little bit of front toe-in, approximately half a degree to one degree.