Tire size from Ford is 215/85R/16. Look kind of small [2WD] I have to get 6 new ones. question is 215s or 235s? I know the spedo will be off-can it be corrected by ford tech with programer or gear[spedo] change needed. Has any one here done the larger tire size swithch? pros/cons. When towing we are towing a max of 12000lbs including the 28 ft tag. Most of time 3500lbs with 14ft loaded with Kart equpt. thanks Al PS there is about 3 inches between the rear set of tires/Ford Spoked alum wheels F/R.