I know it can be changed by modding

but stock S2K oversteer more? or understeer more?

 

From what I hear ap1 and ap2 are different. I've only driven an AP1 hard enough to know they have a decent balance to a point. After that point it likes to oversteer. Since I've owned it I have put AP2 wheels and RE050 Tires and noticed the car to be much more balanced.

 

Stock AP1 with stock tires tends towards oversteer.

Stock AP2 with stock tires tend towards understeer.

Stock AP2 with proper tires is fairly evenly balanced.

 

00-01 Oversteer bias
02-03 Neutral bias (but will oversteer easily)
04-07 Mild Understeer Bias
08+ Understeer bias (like a tricycle, jk)
08CR + Even more than 08 Understeer bias with the 255s on the back.