Originally posted by NegativeC
Front / \
Rear \ /
will turn the best because as the weight shifts to the outside you are basically already turning. Inside rear doesn't do much usually.
However front toe in is very unstable and usually results in worse cornering ability when going fast. You can see if you were taking a fast right (below), the left rear would want to step out and the right front isn't helping to turn the car as much.
Front / |
For autocross situations... Toe in / \ up front is BAD. Toe out \ / front AND rear is good.
Toe in up front makes steering response very mushy. Toe out makes it feel much quicker.
Toe out in the rear really helps the car follow the corners and rotate better.
Zero toe is best for best tire wear.
Road and rally racing will require different settings than autocross.