Hi Jed,
I got the 255/55/18 because:
V-Rated / Stronger construction, they actually weigh 6 lbs more per tire
Sectional width is only .2 inches different from 265/60/18
It was the closest to original diameter / less speedo error
But anyway you cut it, Kumho is an exceptional tire. I know you will be happy with your tires. Good luck with yours.
Howard