My ex-wife's Mazda3 runs 205/50s on a 17X7.5, they work pretty good, but when I got my 17X8 Cobras, they had 205/40s on them and they were too stretched, and rode funny.

So it depends a little bit on the aspect ratio, the lower the ratio, the wider you need to go to avoid stretching. A 205 is only 8" wide at its widest point, so on a 8" rim, the lip of the wheel will be sticking out past the sidewall. I would think a 215(8.5") would be a minimum width for a 8" rim, and would prefer a 225(9"). Personally, I ran 235/55s on my 17X8s and didn't have any issues with rubbing on the fender lip, only on the bottom side of the inner fender, and a narrower tire won't help that. Also note, the offset of your wheels will make more difference than the width of the tire when it comes to avoiding rubbing, and your wheels have quite a bit of offset, so I wouldn't go overboard with skinny tires, and see where you sit once you get down there.

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