I have a Sport coming in 2 wks and have already done my winter tire package research and ready to make a purchase.
1. Only the sports have the bigger brakes.
2. 18" wheels will just fit on the Sport over top the bigger brakes.
3. 17" wheels will fit on the other trims,
4. Apples to Apples 18" tires are way cheaper than 20" tires. I believe tire rack has the Michillin X-ICE Latitude Tours (Which I always buy for all my vehicles, great tires) 18"/65 profile around $190, 20"/50 profile almost $300 ea. Big difference.
5. The Sport & Limited OEM tires are 255/50/20,
Wheels are 8" wide, 5x114.3 stud pattern, 44mm offset, 70.5 bore.
Snow tire equivalent for the 20" OEM's is:
255/65/18 3% larger circumference...seems to be the cheapest and most popular.
245/65/18 1.7% larger circumference and a little thinner to fit on perhaps a 7 or 7.5" wide wheel.
245/60/18 1.5% smaller circumference.
The Costco winter steel wheels for the Ford Explorer 2011-14.
18" Hub Centric Part#X48367...trust me, get Hub Centric wheels
18" Multifit Part# X48827
Personally I'm going with the 255/65/18 and buying a cheap set of 18" aftermarket sport wheels rather than those crappy steel wheels. Although, the steel wheels are much more durable if you should slide into a curb and such. I just couldn't bare to run those ugly steel wheels on a Sport
If I've missed anything or anyone else has some good info on Winters, please post.