wheels size

[DAF]

what size are my origanal rs4 wheels 225/45/17 are they 7.5 or 8.5 wide

 

[jojo]

I would have thought they were either 7" or 7.5" wide for 17" wheels.

 

[dcallaghan]

The 225 in your 225/45/17 gives the width of the suitable tyre. Converting this into inches gives 8.85 inches, so I guess the wheels are 8.5 inches.

The 45 gives the sidewall height expressed as a percentage of the width. Thus the sidewall height is 225*0.45 = 101.25mm. As you are probably aware, the 17 is the wheel diameter in inches.

The tyre diameter should then be 17 * 25.4 = 431.8 + (2 * 101.25) = 634.3mm