I bought a set of wheels and tires off of a 2011 C30; they are the Midir Diamond Cut 18" x 7.5". I thought they were identical to the optional wheels on the 2011/12 C70, and I had credible (or so I thought) info that the 2007-current C70 wheels will fit any year. Anyway, I installed one of the wheels and it looks like the offset is different between the stock 17"s I had and the 18"s... the wheels sit too deep in the wheel well. Does anyone have any info that will help? Do I need spacers? This is my first wheel swap so I'm kind of in the dark. Thanks for your help guys and gals!

Paul

 

Maybe get the stamped number off the inside spoke of your original wheels. We can use it to see what wheel should fit.

 

Both wheels are 7.5" in width. The orginals have an offset of 45. The 18" off C30 have a 52.5" offset. I did some searching and it seems I need 7 mm spacers to make up the difference. What are your thoughts? Thanks!

 

Spacers is the way I'd go. If you've never used spacers before, keep in mind that you'll need to get the correct hub centric spacers and extended bolts. I'm running H&R spacers on both my Volvo's right now and I really like them. I picked them up from iPd, and they'd be able to get you what you need.
The 7mm spacers should bring the wheels out to where your others were but I'd see about going just a little further out to try and flush the wheels and tires with the wheel well. See if 10 or 15mm spacers would took better.

EDIT:
The Midir's will look great on a C70! any chance when you mount the wheels can you post a pic?