215/45 R17 are the standard size tyres that are fitted to the WRX ( MY02 )

Will 225/45 R17 fit these alloys and what is the difference in the two sizes, height, width etc ?

Cheers
Marc.

 

The 1st figure is the width of the tyre in mm, hence 225mm. The second is the wall height as a percentage of the width, 45% of 225 = 101.25mm. The third is the wheel diameter in inches. Using the 3 figures you can calculate the overall diameter of various tyre widths and profiles to keep as close as possible to the manufacturers recommended sizes to retain speedo accuracy and possibly avoid rubbing if you go too big.

215x45x17 have an overall diameter of 625.3mm
225x45x17 are 634.3mm

THIS is handy. But in short, yes they'll fit.

 

Subaru fit 215's to the standard WRX 7" rim and 225's to the STi 7.5" rim must be good reason for that... if you want to go to 225's why not get some STi rims instead.