Attached is from 2010 Toyota Prius Product Info handout. When they say 60 inch front tread width, do they mean track width (ie center of tire to center of tire)?
I think so. There's a clue in the .4" (roughly 10 mm) difference, 15" tires (195 mm width) vs 17" tires (215 mm tread width). Maybe? My brain is full, lol.
I believe Mendel Leisk is correct. If the difference in tires is 10 mm each, the width would go up 20 mm if it was to the outside, and if you went from center to center the difference would be split in two, IE 10 mm. half of the width being on each side of the rim, and half on both sides of the car. I know that sounds really confusing. You should try doing revolutions per mile based....
OK, after further thought, I'm wrong. If half of the width difference is on each side of the rim, which it would be, the width would go up 10 mm. That still means that Mendel Leisk is right, my logic in agreement was just flawed.
It could even be the offset on the 17" stock rims is different, that's another reason resistance is futile.
I think they would use the same offset, so tire wear and alignment angles wouldn't be affected, but anything is possible. Theoretically you could swap between 15, 16 and 17 OE rims with no impact. Of course the difference between theory and reality is huge.
