[Proghound]

Phil, be careful when swapping that the 17" wheels you get have only come from a another C70. You want width of 7.5J and offset of 45 (ET45). This will be stamped on the back of the wheel.

Of the C30/S40/V50/C70 range, only the C70 has 7.5J wheels at 16" and 17" sizes. On the other cars they're narrower, and have a higher offset of 52.5 at all sizes including 18"x8J. While they'd fit the bolt pattern on your car, they'd sit further inboard in the wheel arches.

Even the same-looking styles are actually different sizes: Slackey's five-spoke wheels are called Serapis on the other cars and are 7J wide, whereas they are officially called Serapis C on the C70 and are 7.5J wide. It's similar with Sadira on the C70 which corresponds to (I think) Sagitta on the other models.

I share your pain with the 18" on rough roads, I kept the Syrma's off my previous C70 and traded it in with some secondhand Sadiras on. The current car is now wearing them instead of its 18" Morpheus.