Wheel Arch Height

Park the vehicle on a level surface.
Empty the vehicle so that it is at "curb weight".
NOTE: Empty the trunk or luggage room, load the spare tire, jack and service tools, and fill up the fuel tank.
Set the steering wheel in a straight-ahead position, and stabilize the suspension by moving the vehicle in a straight line for 5 m (16 ft) or more.
Suspend a thread from the wheel arch (point "A" in the figure below) and affix at a position directly above the center of wheel.

Measure the distance between the point "A" and the center of wheel.

Fig 1: Adjusting Wheel Arch Height

Courtesy of SUBARU OF AMERICA, INC.

Model	Tire size	Wheel arch height specification mm (in) (Tolerance: ^{+12 mm}_{-24 mm} (^{+0.47 in}_{-0.94 in} ))
Model	Tire size	Front	Rear
WRX model	235/45R17	375 (14.76)	367 (14.45)
WRX model	245/40R18	370 (14.57)	361 (14.21)
STI model	245/40R18	370 (14.57)	362 (14.25)