What are the pro's and con's of each? The 285's measure a bit smaller at 32.8" than do the 255's at 33.1" but 3/10 of an inch is fairly insignificant. I wonder about the width of the contact patch and the differences it would make for on and off road handling, gas consumption, and tread life. Which tire size would be better suited for dry rocky trails (where I spend most of my off road time), mud, wet forrest trails, sand, rock crawling, snow, ect??? Any other pro's and con's?