I was wondering what makes the Sti brakes "wider," since when you buy wheels they talk about the calipers might get in the way. Is the calipers that are fatter?

 

I think Brembo calipers are bigger and when buying wheels, you need to make sure that the wheel itself will fit over them. I think there are ways to get by that, like using spacers, but yeah.

 

OEM STi brakes are fitted with Brembo calipers and larger rotors than the WRX. The Brembo calipers are physically larger than the WRX 2-pot or 4-pot front calipers, as well as being spaced out further from the hub due to the larger front rotors. This is why wheels must be checked for caliper clearance before tightening the lug nuts. More than one set of front wheels has been ruined/damaged due to insufficient clearance with a big brake kit, Brembo or otherwise.

Even the MY02 through MY05 WRX 16" x 6.5" wheels do not clear the factory 4-pot calipers, with or without raised 'SUBARU' lettering on the calipers.

 

^ what he said. Only good fitment wheels i like that fits 06+ 4pots are the JDM v7 wheels.