Greater Powerful charge( Miniatures Handbook, p. 27)
[Fighter Bonus Feat, General]
You can charge with extra force.
Powerful Charge (MH) , base attack bonus +4, Medium or larger,
As Powerful Charge, but treat yourself as one size category larger than you are. For Colossal creatures, the extra 6d6 points of damage bonus becomes 8d6.
A fighter may select Greater Powerful Charge as one of his fighter bonus feats.