I have two of these balls, i decided to get a second before they stopped making them. They are very strong in the backend and the perfect lane condition for them for me is medium-light with carrydown. It allows the ball to get the length from the shell and then just hook very strong on the back and explode the rack. Imo it is the best of the diesel series and i have sold off the particle, reactive and power diesels but will not sell the 2 particle pearls i own. If you slightly dulled them i am sure they would handle medium-heavy but you would kill the purpose the ball was made for jmo.