What tires/wheels fit under unrolled fenders?

[joe149]

Just bought an '08 Mazdaspeed3, and will be autocrossing it. Would like to put Hoosier A6s on it. Seems reasonable to consider 17" wheels in his case for less unsprung weight (and more weight left in wallet for that matter).
Anyone have a good idea of what size tires will fit under stock fenders/stock suspension - 17" or 18", particularly A6's? Any other tires you'd consider good for autox?
tia,
Joe

 

[RichB]

I would use This Site and try and keep the overal diameter and width the same because the stock set-up is tight in the rear. If you want to go wider you should probably shorten the sidewall height some from the stock dimension to avoid rubbing. This is all also ofcourse if your offset is 40+

An example of going wider and stepping down the sidewall height is going with a 225 / 40 /18 tire which I see a lot of people are doing.

Let me know if this doesn't make sense

 

[unicef]

235/45/17 would have a slightly smaller overall diameter than stock (25.3" compared to 25.6"), and *should* not require rolling of the fenders.