The OE tires are Hankook AS P255/50R20. Remembering the problems the Explorers were having with the Bridgestones, I was concerned, but after a trip of 4000 miles I have confidence in these tires. Some driving was in heavy rain, head winds, cross winds, and even in clear dry weather when, once in a while, when the speedo was showing 3 numbers I had no problem with control.
Keeping an eye on the instant MPG gauge, I noticed when the counties changed, the road surface changed and the gauge would increase or decrease MPG ever so slightly.
We live outside a small town in NM called Ruidoso. We are in the mountains at an elevation of 7000 ft. A few days after returning home from our trip, we had an ice storm. This was a good chance to really test these tires. It is a mile up hill and tight curves to the main road. Keeping the terrain dial in the normal driving position, there was never a hint if losing control. At the end of our road, it is an up hill with a stop sign at the top. Again, no problem with the ice covered road, My hat's off to Ford for their ABS and AWD, and to Hankook for their AS tires.