265's or 285's
 

Im looking to get some new tires now i have 245's Id like to go bigger but do not want to loose much power or mileage so witch would be better for me a 245 = 30.7 "
265 = 31.7 "
285 = 32.9 "
oh and my truck only has 355 gears with a 5.2

RE: 265's or 285's
 

get the 285s and stop there... anything bigger and you'll have to regear. I'd recommend a regear anyway but that's hella expensive.