Hoosier LM40 versus 55

[dirtrace09]

New to Late Model's. We are allowed to run either the LM40 or the 55 tire. What is the difference between the two of them? Also, which one works better in which condition?
Thank you for any help you can give.

[9WRACER]

55's have a plated side wall, makes them stiffer, 40's don't so they roll over more. If you look at a 40 it has d-55 molded into the edge of the tire, come off the same mold.

[latemodel86]

From what I've been told, you only run the LM40 when the track gets SUPER DRY & SLICK...to the point where it has some orange to it, I believe...