A piston for an internal combustion engine including a piston crown having an upper surface and a lower surface; a piston skirt; and a generally cup-shaped undercrown formed on the lower surface of the piston crown and integral with the top portions of opposing side walls of the piston skirt, at least a portion of the surface of the undercrown being rough, defining at least one region of increased surface area, wherein the distance between an uppermost and lowermost points of the surface of the undercrown in the at least one region of increased surface area is in the range of approximately 0.1 mm to 1.0 mm.