Изменяя ширину и диаметр диска, сохранить вылет тем же невозможно. Покажи мне, где написано, что вылет не должен меняться?

Если понять, как влияет вылет или ширина диска/покрышки, то не трудно понять, куда уйдет и как станет колесо в арке

Может стоить изучить схемку вроде этой?
http://w10.desti.ru/Mashina/Tuning/et.gif
Есть некая табличка, которая поможет в дальнейшем, но советую не применять предельные значения из нее.
P11 tire fitments:
*195/60/15 - 24.2" diameter (35-45mm offset required)*(99-01 Touring)
*195/65/15 - 25" diameter(35-45mm offset required)*(99-02 Standard)
205/50/15 - 23.1" diameter (35-45mm offset required)
205/55/15 - 23.9" diameter (38-45mm offset required)
205/45/16 - 23.3" diameter (35-45mm offset required)
*205/50/16 - 24.1" diameter (35-45mm offset required)*('02 Sport)
215/40/16 - 22.9" diameter (32-45mm offset required)
215/45/16 - 23.6" diameter (38-45mm offset required)
225/40/16 - 23.1" diameter (35-45mm offset required)
225/45/16 - 24" diameter (42-45mm offset required)
225/50/16 - on stock 16 inch sport wheels (according to Marty)
205/40/17 - 23.5" diameter (35-45mm offset required)-reinforced sidewall recommended
205/45/17 - 24.3" diameter (38-45mm offset required)
205/50/17 - 25.1" diameter (38-45mm offset required)
215/40/17 - 23.8" diameter (38-45mm offset required)
215/45/17 - 24.7" diameter (40-45mm offset required)
225/40/17 - 24.1" diameter (42-45mm offset required)
225/45/17 - 25.1" diameter (42-45mm offset required)
215/35/18 - 23.9" diameter (38-45mm offset required)-reinforced sidewall recommended
215/40/18 - 24.8" diameter (40-45mm offset required)
225/35/18 - 24.2" diameter (42-45mm offset required)
225/40/18 - 25.1" diameter (42-45mm offset required)
215/35/19 - 24.9" diameter (42-45mm offset required)
225/35/19 - 25.2" diameter (42-45mm offset required)
*stock setup
Note on P11 offsets- All offsets listed assuming the car is not lowered more than 3"... otherwise, fender lip trimming may be required... also, in most cases, a 2-6mm spacer may be used on the rear just for the purpose of making the width of the rear track visually match that of the front(not neccesarily a performance gain).