The standard size 18's that come with the ORA II is P265 60 18 which is the same diameter as the P265 50 20's that come on the Overland. If you go to a bigger or smaller size then your speedometer will be off. Her's a site you can use for comparision.
__________________ Ordered 19 Oct 2013 JGC Limited - Granite/Black - 3.0L ECODiesel - LUX II - NAV - Off Road II- Block Heater. Built - Pending Inspection: (I) 11/13/2013 10:04 PM EST Detroit Jefferson Assembly, MI