You can go as large as 33" w/o a lift kit. Up to 35" tires, no lift, with trimming of the fenders. The minimum wheel size you want is 15" (may require some grinding of the brake calipers, though). The Rubicon has 17" wheels & 32" tires, the Sahara has 18" wheels. Max wheel size really depends on the brand/size tire you buy. The most popular (IMHO) wheels sizes are 15" & 17" wheels. Larger wheels give you better on-road handling, but smaller wheels give you a more cushy ride off-road and more sidewall grippage.
2008 JK Rubi on big tires and stuff, RIPP supercharger.
Various dents and scratches.
Last edited by Acey; 09-12-2012 at 10:30 AM.