PRM, that was my plan as well until I discovered this new size. My understanding is that the new GM full size SUV's come with a 265/65-18 and that is why BFG decided to offer this size. I suppose we should thank the General...
webby, I'm not too worried about ride quality. Some of the reasons I'm buying this thing include the seating capacity, size, it's towing capabilities and the fact that it has a true 2-speed transfer case that can be of use in off-road situations. The OEM tires don't do much to enhance the off or on-road capabilities whereas the BFG All-Terrains will hopefully be a much more capable off-road as well as winter time on-road tire. I have used them on nearly every 4x4 vehicle I have ever owned and I have never found them to be a bad compromise between a street tire and a decent off-road tire for my needs. The Sport Trac will never be a rock crawler or bud bogger as long as I own it and from experience I know the BFG's will do very nicely for everything else.
BTW, I placed my order about an hour ago. I tried to get the dealer to install the BFG's but they wanted about eighty dollars more installed than what I can get them from the Tire Rack for and have them installed by a local tire shop. They did say they would reprogram the computer to adjust for the difference in tire diameters. I did have them order the skid plates for the transfer case and gas tank through their parts dept. The price was $439 which includes labor for the dealer to install. I tried to get the dealer to order them as a factory installed option but they said they could not since that is a fleet only option. I suppose I could shop around for another dealer that might be more willing to do this stuff but I'm tired of screwing around.