Over the last 2 years, I've run 30" Mongrels (33lb) and Moto Crawler (36lb) tires on a XP 4 1000. Now with the XP Turbo, I'm running 32" Mongrels (38lb). A couple observations:
-The ground clearance on the 32's is awesome, very big selling point
-Loud hum once you get over 50mph
-Feels like...