SHELBY GT 350 Member
Joined: Jan 2011
Location: Central Massachusetts
do you know what width wheels you have?
You can find out by taking one off and looking on the back, it should be stamped on there. They are probably 8" or 8.5" wide. If so, you can use 235's for sure.
Take a look on TireRack.com for different tire sizes. They have "specs" tables that show the recommended wheel width for a given tire size, and also the overall diameter. Stock overall diameter is about 27.25", you can go a little bigger than that but not too much.
For the snow I would want the narrowest tire possible (like 225 or even 215 if you can get it) and a relatively high sidewall height (like 55 or maybe 60 for the 215's) -- the narrower tread will bite in better, and the higher sidewall gives a little more ground clearance and clearance to the wheel.
| 2010 GT coupe | Daily Driver with some Steeda and GT500 take-off stuff for the occasional track day