I have no clue what fits on these new mustangs. But I'd say go with a 305/35/18? I don't think the sidewall is going to be THAT flexible with that size though....That's just like any typical tire.
If you want the sidewall to fold, you need to get like a 15" rim (which probably wouldn't even fit over the brake calipers. But you'd be able to run a lot more tire.
__________________

2013 Performance White Boss 302
-Stock
2002 Mineral Gray GT
-VT engines Stage 2 N/A cams, full SLP exhaust, 4.10 gear...etc.
|