The official specs for the OEM wheels are as follows: 215/45r17 17x7J 50mm offset 195/65r15 15x6J 45mm offset When I plug in these numbers into an online wheel offset calculator, it tells me that compared to the 17" wheels, the 15" wheels result in the outside edge being retracted towards the axle by 7.7mm. Then, why does the published track (tread) state that the 15" wheels is wider than the 17" wheels? (10mm, both in F and R) I have the Touring model with 17" wheels, but I also have a set of Nokian Hakka 5 winter tires, 195/65r15 from my prev car. They are in great shape and were not cheap, so I don't want to get rid of them. I have a choice of getting a set of 15" OEM rims off of ebay, or another style altogether. It seems I should aim for an offset of 37 or 38mm to not change the outside edge position. Can anyone with wheel swapping experience comment on my math and see if I'm right? I'd rather have a wider tread without extending beyond the body.
