so backspace is measuring from hub face to inside edge of rim? never heard the term 'backspace'- not here in blighty or in NZ.

 

Correct. Maybe it is more of a US thing.

 

Heres a calculator to help you guys out.

 

Use this too guys, i have found it very helpful

 

If you have the 30mm offset wheels already, try to bolt them on with washer stacks under them at each lug and see how they fit. Vary the number of washers until they fit the way you like them. Measure the stack and make the spacers to match. Best to do this with the axle at ride height.

I have 225s on the back of my RX3 on 16x7s with plenty of room.

 

measuring is good but you're still in the dark. thats the advantage of having a good supply of epsilon lips. we have been trying out different size lips to find the right backspace/size. In fact, I can fit 16x9 in the rear but I wont go to that extend as the inner lip will rub on the frame when cornering.

although backspace and off-set are somewhat "relevant," the rim guy wont know what a backspace is and when he tells you XXX offs-set, you need to know what it means and you better know what it is as if you are wrong, you may not be able to return your rim for an exchange or refund. When I say, you cant use backspace and off-set in the same sentence, I am right period.

 

all these big wheels.. Making me feel inadequit... For i only have 175's on 13 x 5.5:-( they are fun in the wet though.. And do make 120 bhp seem like enough..

 

There is no tire selection for 13" rims except for race version which are too expensive. 14" is in the same category.