Originally Posted by Joe@ApexRaceParts
A square set up will significantly reduce understeer on an otherwise stock car and greatly attributes to a more neutral handling car. The ability to rotate and work the car through the corner also becomes much easier when you have the same amount of grip in the front as the rear, in a square set up. Almost all BMW owners at track days and club races end up using square wheel and tire set ups (unless they have very high power levels) because of the control and ability to manipulate the car in certain ways are much higher when there is greater front end grip. It really comes down to everyone's different preferences with their own car and their driving styles.
Thanks for the insight Joe. What is the preferred square setup? 18x10 or 9.5?