You can charge with extra force.
Prerequisites: Medium or larger, base attack bonus +1.
Benefit: When you charge, if your melee attack hits, it deals an extra 1d8 points of damage (if you’re Medium). For Large creatures, the extra damage is 2d6; for Huge, 3d6; for Gargantuan, 4d6; and for Colossal, 6d6.
This feat works only when you make a charge. It does not work when you’re mounted. If you have the ability to make multiple attacks on a charge, you may apply this extra damage to only one of those attacks in a round.
Special: A fighter can select Powerful Charge as one of his fighter bonus feats.
Source: Miniatures Handbook, page 27.