If you want a wider tire than the stock 225 you can go with a 245/70R16 which is almost the same diameter and will have little error for mileage and speed.
If you search 245/75 on this forum you will find a lot of info on fit issues on the rear with the increase in diameter. Going with a 235/85 will even have greater issues with fit on the rear and maybe even the front (245/75's seem to have no front issues).