I run 38.5x14.50x15 SX's and they are Not to wide,,, IMO I also run them on a 10 wide rim,, the "all around" performance in mud snow and rocks,, cant be beat! The tire pressure needs to dam near be perfect on the road,, but right about 22lb the ride smooth as a baby's ass.. Any thing other than that they will shake you off the road...
lol I have been running this particular tire for 9 years now... And I wont change!