It's about a half inch larger in outer diameter. It should fit without rubbing, but there is precious little clearance around the tire inside the wheel well without any sort of a lift. If it rubs it will be at full lock or full deflection, and it will likely not rub much. Note that it will raise the vehicle about 0.25" off the ground. Changes to the actual speed vs speedometer reading and torque/acceleration will be very minimal.
I upgraded to the Goodyear Wrangler Adventures with Kevlar (formally called Wrangler Silent Armor) in 265/60R18. I have had no problem with them at all. In fact we've been a lot of places the OEM tires would have just cried looking at.