No tire manufacturer recommends a tire wider than a 285 on a 9.5" rim width. Will a wider tire fit? Sure you can shoe horn it on the wheel, but the tire was not constructed to work on a narrower rim. The stock wheel can be widened.
305x35x20 MT's will fit stock wheel but it will result in slightly fatter sidewall width with slightly smaller footprint that a wider...say 11" rim. That's what MT tech told me after suggesting NOT to use the 305 with stock rims. But after 2 seasons i swapped those same 305's from stock rims to wider TSW wheels with no issues.
Geez, from what I'm seeing on some of the online tire retailers (tire rack, discount tires online), there sure aren't many options for a stock tire size replacement.
True that. Ford should have at least put a 10"wide wheel on these cars. Widening your stock wheel by an inch, opens you up to a better selection. If you go aftermarket, research offsets carefully, as it makes a big difference as to how a tire fits inside the wheel well with larger rubber.