I believe the stock tires on a Rubi are 255/75R17 Bf Goodrich Mud Terrains. If that is the size then they are roughly equivalent to 32.1 inches tall and 10 inches wide. A 285/70R17 would be roughly equivalent to 32.7 inches tall and 11.2 inches wide. As for the height i really dont see a problem in clearing a tire thats 1/2 an inch taller. As far as it being over an inch wider you might possibly have rubbing issues with the stock back spacing of the wheels but then again i own a Commander so i could be totally wrong. I do know that any wider tire on the commander would require either a new set of wheels with the proper backspacing or wheel spacers!
07 Jeep Commander 4.7 L
OME HD Suspension Lift | Jeepin by AL HD UCA's | Rusty's Rear Adjustable Track Bar | JKS Rear Sway Bar Quick Disconnects | Black Rock Series 997 Wheels | Fred Goeske .25 Inch Hub/Wheel Centric Spacers | 285/70R17 Goodyear Wrangler MT/R's w/Kevlar | Air Flow Snorkel | Flowmaster 50 Series SUV Muffler | Superchips Flashpaq | Mopar Skids | 4xGuard Belly Guard